PT3E-0646

FI-900
Optical Interferometric Gas Monitor
Operating Manual(PT3E-064)

Thank you for choosing the FI-900 Flame-proof Optical Interferometric Gas Monitor.
This operating manual is a guide to using the FI-900. Be sure to read and fully understood thecontents of this manual before using the product. This applies both to first-time users and those whohave previously used the product.
This manual uses the following headings to ensure safe and effective work:

DANGERThe DANGER sign indicates that improper handling of the product may
result in death, severe injury, or serious property damage.

WARNING

The WARNING sign indicates that improper handling of the product may
result in severe injury or serious property damage.

CAUTION

The CAUTION sign indicates that improper handling of the product may
result in minor injury or minor property damage.

* NOTEThe NOTE sign indicates recommendations for product handling.

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==== Contents ==================================
1. Important Safety Information ...................................................................................... 5
1-1. Danger items ........................................................................................................................ 5
1-2. Warnings .............................................................................................................................. 6
1-3. Precautions .......................................................................................................................... 8
1-4. Checking standards and explosion-proof specifications ....................................................... 9
1-5. Explosion-proof performance information (Japan Ex specification) .................................... 10
1-5-1. About the FI-900 .................................................................................................... 10
1-5-2. Technical data ....................................................................................................... 10
1-5-3. System configuration for use in hazardous locations ............................................. 11
1-6. Explosion-proof performance information (ATEX/IECEx/UKEX specification) ................... 12
1-6-1. About the FI-900 .................................................................................................... 12
1-6-2. Technical data ....................................................................................................... 12
1-6-3. System configuration for use in hazardous locations ............................................. 13
1-7. Safety notices ..................................................................................................................... 14

2. Product Configuration ............................................................................................... 17
2-1. Product intended use and features..................................................................................... 17
2-2. Exterior drawings................................................................................................................ 18
2-3. Accessories ........................................................................................................................ 19
2-3-1. Standard accessories ............................................................................................ 19
2-3-2. Maintenance parts ................................................................................................. 19
2-4. Front panel part names and functions ................................................................................ 20

3. Installation .................................................................................................................. 21
3-1. Installation location precautions ......................................................................................... 21
3-2. Product installation procedures and precautions ................................................................ 22
3-3. Cable connections .............................................................................................................. 23
3-3-1. External terminal plate and cable connections....................................................... 23
3-3-2. Recommended cables ........................................................................................... 24
3-3-3. Cable routing and connection procedures ............................................................. 25
3-3-4. Protective grounding .............................................................................................. 27
3-3-5. Electrical installation precautions ........................................................................... 28
3-4. Pipe installation .................................................................................................................. 30
3-4-1. Sampling systems.................................................................................................. 30
3-4-2. Pipe installation precautions .................................................................................. 31

4. Measuring Mode Operating Procedures .................................................................. 32
4-1. From display after power-on to measurement start ............................................................ 32
2 / 844-2. Reference gas calibration procedure.................................................................................. 33
4-3. Shutdown procedure .......................................................................................................... 33
4-4. External output signal ......................................................................................................... 34
4-5. Concentration alarms and out of measurement range alarms ............................................ 35
4-6. Self-diagnostic monitoring function..................................................................................... 37
4-7. Contacts/display/signal output on returning to normal ........................................................ 38
4-8. LCD screen display order of priority ................................................................................... 39
4-9. Switching to other modes ................................................................................................... 40

5. Check Mode Operating Procedures ......................................................................... 41
5-1. Check mode menu items .................................................................................................... 42
5-2. Items and details ................................................................................................................ 43

6. Setup Mode Operating Procedures .......................................................................... 49
6-1. Setup mode menu items .................................................................................................... 51
6-2. Items and details ................................................................................................................ 52

7. Maintenance ............................................................................................................... 67
7-1. Maintenance intervals and items ........................................................................................ 67
7-2. Daily maintenance .............................................................................................................. 67
7-3. Monthly maintenance ......................................................................................................... 68
7-4. Six month maintenance ...................................................................................................... 69
7-5. Recommended periodic replacement parts ........................................................................ 69

8. Storage, Relocation, and Disposal ........................................................................... 70
8-1. Procedures for storage or when not in use for extended periods ....................................... 70
8-2. Procedures for relocation or reuse ..................................................................................... 70
8-3. Product disposal ................................................................................................................. 70

9. Troubleshooting......................................................................................................... 71
9-1. Abnormality <FAILURE> .................................................................................................... 71
9-2. Outside specification range <OUT OF SPECIFICATION> ................................................. 74
9-3. Maintenance request <MAINTENANCE REQUIRED> ....................................................... 76
9-4. Function checking <FUNCTION CHECK> ......................................................................... 77
9-5. Concentration alarm <ALARM> ......................................................................................... 78
9-6. Caution display <CAUTION> ............................................................................................. 79
9-7. Other displays .................................................................................................................... 80
9-8. Unrelated to screen display ................................................................................................ 80

10. Product Specifications ............................................................................................ 81
10-1. Standard specifications ...................................................................................................... 81
10-2. Detection principle .............................................................................................................. 83
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11. Terminology ............................................................................................................. 84

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==== 1.

Important Safety Information ================

1-1. Danger items

DANGER<Explosion-proofing>• Install the product in accordance with the installation requirements.
• Do not open the cover during operation.
• Be sure to turn off the power before replacing fuses.
(Fuse specifications: 250 V, 1 A, φ5 × 20 mm time-lag fuse)• Do not disassemble or modify the product or alter the settings unnecessarily.
• Contact Riken Keiki for readjustment, including gas calibration, and parts
replacement.
• Do not attempt to replace parts or components yourself if the transparent window ofthe display cracks, you see abnormalities in the explosion-proof bonding surface, orthe fastening screws or bolts have been changed or lost. Contact Riken Keiki
immediately.
• Be sure to perform regular maintenance.
• Use suitable cables for wiring.
• Use insulation sheathed round crimped terminals for electrical connections, andattach them safely making sure they are not loose or twisted.
• Use a crimped terminal for connecting the grounding cable to the grounding terminal,
and use grounding cable with a cross-sectional area of at least 4 mm2 for externalterminals.
• The transparent window of the display is made of polycarbonate resin. Note that it
may be affected by environments in which substances such as toluene, benzene,ammonia, or aromatic hydrocarbons are present.
• Do not attempt to repair the explosion-proof bonding surface.
• Use the control key (magnet) specified by Riken Keiki.
• Gas conditions (explosion-proof requirements)
Maximum flow rate: Target gas (GAS IN):

1 L/min

Reference gas (REF IN): 0.5 L/min
Pressure:GAS IN/REF IN/OUT:

80 kPa to 110 kPa

Temperature:

GAS IN/REF IN/OUT:-20 °C to 57 °C(Japan Ex spec.)

GAS IN/REF IN/OUT:-20 °C to 60 °C(ATEX/IECEx/UKEX spec.)

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1-2. Warnings

WARNING<Explosion-proofing>
Do not open the cover on the front of the main unit in situations where an explosive
atmosphere may be present.

WARNING<Power source>• Before turning on the power for the product, be sure to confirm that the power source
meets the specified voltage requirements. Do not use unstable power sources; doing so
may lead to malfunctions.
• The internal device settings differ between AC and DC power supply models. (See thefollowing diagram.)
Incorrect settings or an incorrect power source will damage the product.
Check the model specifications to ensure that the correct power source is used.

AC model power source terminal plate unit

DC model power source terminal plate unit

<Protective grounding requirement>
Do not cut the protective grounding cable of the product or disconnect the protective
grounding terminal.
<Defects involving protective functions>
Before operating the product, check the protective functions for defects. Do not operate
the product if you find potential defects in protective functions, including protective
grounding.
<External connections>
Connect to a protective ground before connecting to external devices.

6 / 84WARNING
Sampling point pressure• The product is designed to draw in gas at atmospheric pressure. There is a danger that target
gas may leak from inside the product if an excessive pressure is applied to the gas inlet (GASIN) or outlet (GAS OUT) of the product. Avoid excessive pressure during use.
Reference gas calibration in surrounding atmosphere• When reference gas calibration is performed in the surrounding atmosphere, check theatmosphere for freshness before starting. Calibrating in the presence of interference gases(gases other than the target gas and base gas) is hazardous preventing correct
measurement/monitoring.
Miscellaneous• Do not draw in gas at high concentrations exceeding the measurement range upper limit. Doingso will produce inaccurate readings.

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1-3. Precautions

CAUTION
Do not use walkie-talkies near the product.
Radio waves from walkie-talkies or other radio transmitting devices near the product orcables may affect readings. If you use walkie-talkies or other radio transmitters, use inareas where they will not affect the product.
Wait at least 5 seconds after turning off the power before turning back on.
The product may not function correctly if the power is turned back on within 5 seconds.
Do not disassemble or modify the product or alter the settings unnecessarily.
Never attempt to disassemble or modify the product. Doing so will void productperformance guarantees.
Additionally, altering the settings unnecessarily without a proper understanding of thedetails may prevent correct operation. Use the product correctly in accordance with thisoperating manual.
Avoid long-term contact of organic solvents on the window plate.
The display window plate is made of polycarbonate resin. Long-term contact with organic
solvents (liquid or high concentration vapor) may result in discoloration or deformation.

CAUTION
The product cannot be used to measure low-volatility solvents that may condense (liquefy) inside
the product or in pipes leading to the product.
The product cannot be used to measure high-humidity solvent gases that may condense inside
the product or in pipes leading to the product.
Do not use the product near to devices that may significantly disturb power source waveforms(e.g., electric welding equipment). Similarly, do not use the product on the same power supply
circuit as devices that can significantly disturb the power source waveform.
Carefully manage ambient temperatures to prevent the target solvent from condensing(liquefying) inside the product or in pipes leading to the product.

8 / 841-4. Checking standards and explosion-proof specifications
This instrument has some specification depends on standard and explosion proof certificate. Pleaseconfirm the detector specification before using. Please refer Declaration of Conformity that is at theend of this manual if you have CE/UKCA marking type (DC specifications only).
You can confirm instrument specification to see name plate as follows.

Ex marking

Japan Excertificate

UKCA marking
CE marking

UKCA marking
CE marking
ATEX/IECEx/UKEX,
CE/UKCA marking spec.
name plate

Japan Ex spec. name plate

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1-5. Explosion-proof performance information (Japan Ex spec.)
1-5-1. About the FI-900
The FI-900 incorporates a refractometer in the sensor unit. The concentration is calculated from thevariations in refractive index due to the measured detection target gas, and a 4-20 mA signal anddigital signal are output. The product can be connected to a recorder to record the gas concentration
calculated from refractive index variations and to a programmable controller for control purposes. Itfeatures three contacts, which are activated by gas alarms and device faults.

1-5-2. Technical data
Explosion-proof construction

Flame-proof enclosure

Certification number

TC21460

Explosion-proof class

Ex d IIB+H2 T4

Ambient temperature-20 °C to 57 °C

Ratings

Power source

100 V AC / 125 mA to 240 V AC / 80 mA,
50/60 Hz, 24 V DC / 205 mA

Transmission signal
output24 V DC / 0 to 22 mA

Transmission signal
input/output

RS-485

Contacts(Contact capacity)

30 V DC / 2 A (resistance load)
30 V DC / 2 A (resistance load)
30 V DC / 2 A (resistance load)

Applicable standards

Manufacturer:

JNIOSH-TR-No. 43 (2008)

Riken Keiki Co., Ltd.
2-7-6 Azusawa, Itabashi-ku, Tokyo 174-8744, Japan
Website: https://www.rikenkeiki.co.jp/

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1-5-3. System configuration for use in hazardous locations
The FI-900 features a flame-proof enclosure (explosion-proof class: Ex d IIB+H2 T4) enabling use inZone 1 locations. However, connected power supply and display units must be installed in nonhazardous locations if they do not have an explosion-proof construction.

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1-6. Explosion-proof performance information (ATEX/IECEx/UKEX
spec.)
1-6-1. About the FI-900
This product is a fixed gas monitor that makes measurements by drawing in gas at constant flow rate.
It can be used with a DC power source.

1-6-2. Technical data
Name:

REFRACTIVE-INDEX METER

Type

:

FI-900Protection Method:

Flameproof enclosure “d”

Certificate Number:

IECEx DEK 12.0058X
DEKRA 12ATEX0187X
DEKRA21UKEX0365X

Group

:

II

Category:

2G

Type of Protection and Marking Code:Ex db IIB+H2 T4

Equipment Protection Level:

Gb

Ambient Temperature:-20 °C ≤ Ta ≤ +60 °C

Supply voltage:

24 V DC / 190 mA

Contact output:

30 V DC / 2 A

Output signal:

4-20 mA (24 V DC / 20 mA)

Digital communication:

RS-485:EN IEC 60079-0: 2018, EN 60079-1: 2014
IEC 60079-0: 2017, IEC 60079-1: 2014
BS EN IEC 60079-0:2018, BS EN 60079-1:2014

Electrical Data

Applicable Standards

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1-6-3. System configuration for use in hazardous locations

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1-7. Safety notices
WARNING•

Do not open the cover on the front of the detector in situations where an explosive atmosphere may
be present.

CAUTION•Install the product in accordance with installation requirements.

•

Do not open the cover on the front of the detector during operation.

•

Be sure to turn off the power before replacing fuses.
(Fuse specifications: 250 V, 1 A, φ5 × 20 mm time-lag fuse)•

Do not attempt to disassemble, modify, or alter the product.

•Contact Riken Keiki for product adjustment, including calibration and parts replacement.

•

Do not attempt to replace parts or components yourself if the window plate cracks, you see
abnormalities in the explosion-proof bonding surface, or the fastening screws or bolts have beenchanged or lost. Instead, contact Riken Keiki.

•

The transparent window is made of polycarbonate resin. Note that it may be affected byenvironments in which substances such as toluene, benzene, ammonia, or aromatic hydrocarbons
are present.

•

Contact Riken Keiki if any abnormalities are discovered.

•

Perform regular maintenance. (For details, refer to “7. Maintenance”.)•

Use suitable cables.

•

Use round crimped terminals for electrical connections, and attach them safely making sure they
are not loose or twisted.

•

Use a crimped terminal for connecting the grounding cable to the grounding terminal, and use
grounding cable with a cross-sectional area of at least 4 mm2 for external terminals.

•

Do not attempt to repair component faces affecting the explosion-proof construction.

•

Use “A2-70” property class stainless steel for all hexagon socket bolts.

•

Use cable lugs on internal and external grounding connections to prevent twisting.

•Insert cable lugs for internal grounding connections between washers and toothed washers.

•

Use the control key (magnet) specified by Riken Keiki.

•Gas conditions (explosion-proof requirements)
Gas types
The product cannot be used with IIC gases other than H2.
Maximum flow rate
GAS IN (target gas): 1 L/min; REF IN (reference gas): 0.5 L/mPressure range
GAS IN/REF IN/OUT: 80 kPa to 110kPa
Temperature
GAS IN/REF IN/OUT: -20 °C to 57 °C (Japan Ex spec.)
GAS IN/REF IN/OUT: -20 °C to 60 °C (ATEX/IECEx/UKEX spec.)
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•If the target gas fed to and discharged from the FI-900 contains oxygen, the oxygen concentration
will lower than oxygen concentrations in the normal atmosphere.

•

Make sure that the target gas fed to and discharged from the FI-900 does not remain in the
explosive concentration range for extended periods or frequently and continuously.

•

Purge gas flow passages within the FI-900 using the base gas before turning on the power.
Purge the gas flow passages within the FI-900 using the base gas before turning off the power.

•

Confirm that there are no problems with gas containment in regular maintenance.

Grounding terminals

Internal grounding
terminal
Grounding terminals

External grounding terminal

Cable glands
Internal dia.

Internal dia.

Internal dia.

Rubber sealinternal dia.

Rubber seal

WasherClamp washer

Table 1. External cable inlet parts diameters
Rubberseal

Cable
External
diameter

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WasherClamp
washerInternal dimeter

Install the cable glands as shown in the following diagram:Interior

Order of cableconnection procedure
5. Washer
4. Rubber seal
3. Washer
2. Clamp washer
1. Cable gland

Exterior
Cable

Tighten cable glands to a torque of at least 40 N m.

Special conditions for safe use•

Do not attempt to repair connections affecting the explosion-proof construction.

•

Use “A2-70” property class fasteners.

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==== 2.

Product Configuration =====================

2-1. Product intended use and features
This product is a flame-proof construction (explosion-proof class: Ex d IIB+H2 T4) fixed gas Monitor
intended for continuous measurement and monitoring of concentrations of various gases, including
atmospheric toluene, atmospheric acetone, and hydrogen in nitrogen (limited to gas types andmeasurement ranges described in the separate “Target Gas Specifications”).
The product applies the optical interferometric method to measure concentrations. Measuring
variations in refractive index enables highly accurate determination of target gas concentrations. The
sensitivity of the optical interferometric sensor is determined by the length of the chamber throughwhich the gas flows. This allows sensitivity to be maintained consistently over extended periods.
The product includes self-monitoring and diagnostic functions complying with the NAMUR NE107
standard (self-monitoring and diagnostics of field devices), which enable real-time monitoring of the
product state and the display and notification of abnormal state and maintenance request informationon the LCD screen.
The product features a fully-independent modular configuration comprising separate units. This allows
rapid repair and recovery in the field by simply replacing the unit in question if a fault should arise.

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2-2. Exterior drawings
4-M8 mounting hole
Eye bold (×2)

Display

External cable inlet(5 locations)

18 / 84

2-3. Accessories
2-3-1. Standard accessories•

Operating Manual•Target Gas Specifications•

Dedicated control key•

Hex key wrenches (2 mm and 6 mm, ×1 each)•

Fuses (250 V, 1 A, φ5 × 20 mm time-lag fuse, ×2)

CAUTION•

Use the dedicated control key provided to operate the product. The product may not accept key
operation commands correctly if an object other than the supplied control key is used.

•

The control key used for adjustment incorporates a powerful magnet. Holding the control key
close to credit cards or IC cards may corrupt data recorded on these items.

2-3-2. Maintenance parts
The product does not include any consumable parts that require periodic replacement. Refer to “7-5.
Recommended periodic replacement parts” for information on recommended periodic replacement
parts for use under special conditions.

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2-4. Front panel part names and functions① MODE/ESC key② POWER lamp (green)③ ALM1 lamp (red)④ ALM2 lamp (red)⑤ FAULT lamp (orange)

①

②

⑦

⑧

③

④

⑤

⑨

⑥

⑩

Key for selecting other modes from measuring mode
[Used to abort processing]Illuminates when the power is turned on. Flashes when checking
functions.
Illuminates in conjunction with the first concentration alarm state.
Illuminates in conjunction with the second concentration alarmstate.
Illuminates when abnormal (FAILURE) conditions arise.

⑧ LCD screen

Key for performing reference gas calibration
Hold down for at least 3 seconds to calibrate.
[Used to move the cursor and to increment setting values]
Key for selecting the display contents in measuring mode
[Used for confirming processing]
Displays measurements and the product operating state.

⑨ IrDA communication
port

IrDA communication port for maintenance use. Used to load event
logs and daily log information stored in the product⑩ ▼/REF. key

Key for performing reference gas checks
Hold down for at least 3 seconds to check.
[Used to move the cursor and to decrement setting values]⑥ ▲/REF.CAL key⑦ DISP/SET key* The descriptions in square brackets refer to operations when not in measuring mode.
All keys described above are operated using the control key
provided. Press the control key against the key marking position
for a few seconds to operate the corresponding key.
In this operating manual, “Press the XYZ key” means to press thecontrol key against the corresponding marking, such as “●”, “▼”, or“▲”.

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Control key

==== 3. Installation ===============================
3-1. Installation location precautions
Use the product only with a sampling system specified by Riken Keiki (or an equivalent cubicle, etc.).
Avoid installing in locations like those described below:① Locations exposed to oil or chemicals② Locations subject to vibration③ Locations where radio waves or noise④ Locations where the product is likely to fall orare emitted

may be exposed to impact⑤ Locations outside the⑥ Locations that prevent maintenance

operating temperature range
Locations subject to direct sunlight orradiant heat

Locations where work is hazardous

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3-2. Product installation procedures and precautions
Install the FI-900 and samplingsystem by bolting to a solid
wall or self-standing rack.

Provide maintenance space
shown in the diagram to theright to allow maintenancework on the product.
Be sure to provide
maintenance space whenplanning and carrying out
installation work.

Maintenance space (units: mm)

CAUTION•

Take care not to expose the product to impact, such as by dropping, duringtransportation and installation.
Failure to do so may damage the product and impair explosion-proof performance.

•

When installing the product on a self-standing rack (fixed type), make sure the rack issecured with anchor bolts.

•

When securing the product to a wall, be sure to mount correctly to a wall capable ofbearing the weight of the product.

•

Make sure no dust or other foreign matter gets into the product during installationwork.

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3-3. Cable connections
3-3-1. External terminal plate and cableconnections<Terminal plate details>
Opening the front cover of the FI-900 reveals theterminal plate shown in the diagram below.
The terminal plate is configured as shown in thefollowing table.

First alarm
contacts

FIRST
ALARM
CONTACT

Operate in conjunction with the first concentration alarmstate.*
No-voltage contact; contact capacity: 1 A, 30 V DC
(resistance load)

Second alarm
contacts

SECONDALARM
CONTACT

Operate in conjunction with the second concentration alarmstate.*
No-voltage contact; contact capacity: 1 A, 30 V DC
(resistance load)

Fault alarm
contacts

FAULT
ALARM
CONTACT

Operate when abnormal (FAILURE) conditions arise.*
No-voltage contact; contact capacity: 1 A, 30 V DC
(resistance load)

①
②
③
④
⑤
⑥
⑦
⑧

Power
terminals

FG

Function ground (EARTH)

L/+

100 V to 240 V AC ±10 %, 50/60 Hz, max. 20 VA
or 24 V DC ±10 %, max. 6 W(DC power supply only for ATEX/IECEx model)

N/−⑨* Operation for standard settings
A

⑩
⑪
⑫
⑬

RS-485interfaceconnectors⑯

G

Input/output terminal for RS-485 (Modbus) communication

Y
Z

⑭
⑮

B

4-20 mA
output signal

(+)
(−)

4 mA to 20 mA DC (insulated, current discharge type), maximum
load resistance 300 Ω
Minimum resolution 0.01 mA or less

The terminal screws on the terminal plate are M4 screws. Connect cables with M4 insulation sheathedround crimped terminals fitted to the ends.

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3-3-2. Recommended cables
Connected toPower (AC) line
Power (DC) line
4-20 mA line
Contact ×1 line
Contact ×2 lines
Contact ×3 lines
RS-485 line

Recommended cableCVV 1.25 mm2, 3-core
CVV 2 mm2, 3-core
CVVS 1.25 mm2, 2-core
CVVS 2 mm2, 2-core
CVVS 1.25 mm2, 2-core
CVVS 2 mm2, 2-core
CVVS 1.25 mm2, 2-core
CVVS 2 mm2, 2-core
CVVS 1.25 mm2, 4-core
CVVS 2 mm2, 4-core
CVVS 1.25 mm2, 6-core
CVVS 2 mm2, 6-core
KPEVS or other shielded twistedpair cable (0.75 mm2), 2 pairs

Cable finished external
diameter
φ10.0
φ11.0
φ10.0
φ11.0
φ10.0
φ11.0
φ10.0
φ11.0
φ11.0
φ12.0
φ13.0
φ14.0
φ11.0

*NOTE
Be sure to check the finished external diameter. This value varies slightly from manufacturer tomanufacturer.

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3-3-3. Cable routing and connection procedures
When connecting cables, insert the cables through the ① cable gland, ② clamp washer, ③
washer, ④ rubber seal, and ⑤ washer in the sequence shown in the lower right diagram below
before inserting into the cast casing through the cable inlets. Attach insulation sheathed round crimped
terminals to the ends and connect to the terminal plate.
Close unused cable inlets with rubber seals and sealing plugs, as shown to the left in the following
diagram.

Locking set screw
Cable inlet (5 locations)⑤ WasherRubber seal

④ Rubber seal
③ Washer② Clamp washer(Note orientation)

Sealing plug
① Cable gland

CAUTION•

Tighten cable glands and sealing plugs to a torque of at least 40 N⋅m.

•

If tightening the cable glands and sealing plugs presents difficulties, apply grease to the screw
thread and tighten using the appropriate tool.

•Once the cable glands and sealing plugs have been tightened, secure with set screws to keepthem from coming loose.

•

Ground the shield on CVVS cables to the casing interior to improve noise resistance.

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The rubber seals, washers, and clamp washers required for the cable connections will differ
depending on the finished external diameter of the cables being used. The following table summarizes
the correspondence between the internal diameter of the individual components and the cable finishedexternal diameter. Order the required components from Riken Keiki to match the cable being used.
Cable finished external
diameter(mm)

Rubber sealinternal diameter (mm)Washerinternal diameter (mm)Clamp washer
internal diameter (mm)φ10, φ10.5

φ11

φ12

φ10.8

φ11, φ11.5

φ12

φ14

φ11.8

φ12, φ12.5

φ13

φ14

φ12.8

φ13, φ13.5

φ14

φ14

φ13.8

Internal dia.
Internal dia.

Internal dia.

WasherClamp washer

Rubber sealinternal dia.

Rubber seal

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3-3-4. Protective grounding
Ground the product using the external grounding terminal shown in the following diagram.

External grounding
terminal

WARNING•Be sure to ground the product before turning on the power.

•

Be sure to provide grounding. This is required for the stable operation and safety ofthe product.
Never connect the grounding cable to a gas pipe.

•

Use grounding equivalent to Class D grounding (grounding resistance 100 Ω or less).

•

The grounding cable should be fitted with cable lugs and connected to the groundsafely, free of slack or twisting.

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3-3-5. Electrical installation precautions
An unstable power supply or noise carried by the cables may result in malfunctions, false alarms, or
faults.
① Use a stable power supply for the system.
(1) The power supply for this product must meet the following requirements:
Power supply voltage: 100 V to 240 V AC ±10 % [AC model]
24 V DC ±10 % [DC model]
Permissible momentary power failure time: Not more than approx. 40 ms(A power failure of 40 ms or more may result in restarting.)
Deploy an external uninterruptible power supply or similar system to guarantee continuous
operation and functionality.
(2) Do not configure the power supply line in parallel with other high voltage or large current lines.
② Provide anti-noise measures to suit the installation environment.
(1) Lightning surge protection
Equipment installed outdoors at factories, etc. is susceptible to lightning strikes. Lightning
constitutes a massive emission source and cables act as receiving antennas, which can resultin damage to devices connected to the cables. Additionally, note that inductive lightning surges
due to lightning strikes cannot be entirely prevented, even if cables are installed in metal ducts
or buried underground. The following preventive measures however are available. The
appropriate countermeasures should be put in place before use.
<Protection using lightning arrester (cable protector)>
A lightning arrester can be installed before the field devices and central processing equipment
to protect against the possibility of inductive lightning surges transmitted through the cables.
Lightning arresters are inserted at the various points where cables enter the building fromoutside. Lightning arresters include a circuit to remove surge voltages that might damage fielddevices.
(2) Power line anti-noise measures
The following methods are available to reduce the effects of electromagnetically induced noiseand electrostatically induced noise from power lines. The appropriate countermeasures shouldbe put in place before use.
<Isolation from power lines>
Signal cables should be kept away from power lines, and should not be laid in parallel where
possible. Intersections should be at right angles.
<Electrostatic shielding>Signal cables should have shielding which is grounded. Electrically isolate cables from powerlines—for example, by installing power lines in steel conduits, placing grounded metal partition
plates between them, or placing them in separate metal ducts.
Surge noise is caused by lightning strikes and other factors. Ground devices to protect against
such noise sources.

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CAUTION
Take care to avoid damaging internal electronic circuits during wiring work.

CAUTIONA de-energized b contact (break contact) may cause a momentary open operation due to physicalimpact such as an external force.
If a b contact is used as an alarm contact, implement measures to account for such momentary
operations—for example, adding a delay operation (of approximately 1 second) to the signal on theb contact receiving side.
When controlling a line on which large inductive loads occur, deploy protective measures for the
product contacts, referring to the following diagram.

Coil

Load

FI-900

ContactPowersourcePowersourceExternal (low voltage)relay* SK1/SK2: Surge absorber•

Link the circuits (contact amplification) using an external relay. Add a surge absorber (SK1)
appropriate for the rating to the external relay.

•

Add a load in the form of a surge absorber (SK2) as necessary to the load side of the external
relay.

•

Depending on load conditions, it may be better to add the surge absorber to the contact side.
Check load behavior to determine the optimal location.

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3-4. Pipe installation
3-4-1. Sampling systems
The FI-900 must be used correctly in conjunction with a sampling system to ensure that it operates tothe expected level of performance. The following diagrams show typical sampling circuits for acharging arrangement from a pressurized line and a suction arrangement from an atmosphericpressure line.

Pressurized line charging
arrangement

Atmospheric pressure line
suction arrangement

The product requires the application of constant pressure with a pressure difference of approximately
5 kPa between GAS OUT and GAS IN. The application of constant pressure with a pressure
difference of approximately 5 kPa is also required between REF IN and GAS OUT.
The sampling system of the pressurized line charging arrangement includes a precision reducing
valve at the GAS IN and REF IN sides to supply target gas and reference gas at constant pressure.
Adjust the precision reducing valve so that the flow rate readings coincide.
The sampling system of the atmospheric pressure line suction arrangement uses a pump to generate
negative pressure. Adjust the needle valve to achieve the specified negative pressure so that the flowrate readings coincide. If the pump has a large suction capacity, the negative pressure must be
controlled by including a bypass line, as shown in the piping diagram above. Install a needle valve orother such device to regulate pulsing between the pump and the product because of the possibility ofreading fluctuations due to pump pulsing.
The product requires a flow of reference gas into GAS IN to confirm and adjust the zero point(reference gas calibration). The design must include a three-way valve or similar device to enablereference gas to be fed to GAS IN.
The OUT side of the sampling system must be maintained at constant pressure. It should normally bekept open to the atmosphere. Gas can be discharged to an exhaust duct at approximately
atmospheric pressure (atmospheric pressure ±3 kPa), if available.
Other forms of customization are also possible, as required, including an inline filter to remove dust
and the calibration gas IN pipe. Contact Riken Keiki for more information.
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3-4-2. Pipe installation precautions•

Pipes used should be made of materials such as copper, stainless steel, or Teflon. Avoid materials
that could cause adsorption or corrosion. The following precautions must also be observed when
installing pipes:•

Increasing the length of the GAS IN side pipe will increase the time taken for the target gas toarrive. It may also increase adsorption effects of solvent vapor on the pipe, delaying response andlowering readings. Take suitable precautions—for example, making the GAS IN pipe as short as
possible or including a bypass line.

•

Allow the target gas to approach ambient temperature before supplying to the sampling system. If
there is a danger of drain or dust ingress, install traps and filters to prevent ingress of foreign
matter.

•When sampling gas from hot and humid atmospheres or at conditions close to the saturated vapor
concentration, measurement will be prevented if gas condenses inside the sampling pipes. Work
with extreme care when installing pipes. Avoid “U” or “V” layouts.

•

Determine the sampling inlet for the sampling gas after carefully considering gas flow inside thesampling gas line, gas generation process, and other factors. Avoid sampling gas from the bottomof pipes, tanks, or equipment.

•Gas should normally be discharged to the open atmosphere. If the end of the discharge pipe islocated outdoors, bend downward to keep rain from entering the pipe. If discharging back into an
exhaust duct or the like, keep pressure fluctuations within atmospheric pressure ±3 kPa and avoid
sudden changes.

•

If flame arresters are provided in the line as a safety precaution, these should be installed on boththe GAS IN and GAS OUT lines.

•

Cutting pipes may reduce the internal diameter of the pipe at the cut face. Be sure to widen theinternal diameter using a file or similar tool. Also be sure to clean the pipe interior using
compressed air or the like to blow off any remaining swarf before connecting to the product.

•

Determine the sampling inlet for the target gas after carefully considering gas flow inside the target
gas line and mixing spots (unevenness) due to the manufacturing process of fuel gases

CAUTION
This product requires appropriate pipe installation (including choice of materials) to suit
the sample gas type and installation conditions. Contact your sales agent or retailer if
you have any questions about pipe installation.

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==== 4. Measuring Mode Operating Procedures ========
4-1. From display after power-on to measurement start
When the power is turned on, the self-diagnostic function runs, and the initial screen is displayed forapproximately 5 seconds before switching to the warm-up display screen.

After approx.
5 seconds

Initial screen

Warm-up display screen“WARM UP” may be displayed for approximately 60 seconds after the initial screen (Off by default).
Relatedsections“4.6

Self-diagnostic monitoring function”“C.03.-- 4-20 mA setting state checking “4-20mA PARAMETER””“S.02.-- 4-20 mA output signal setting “4-20mA SETUP””

Measurement starts once warm-up is complete. A screen as shown below appears whenmeasurement starts.
Displays the target
gas type.

Displays the units
for measurements.

Displaysmeasurement
results.

Displays the reference gas (REF) flow
rate. Adjust so that the black circle isbetween the two vertical bars indicating
the upper and lower limits.*
The flow rate will be approximately
10 mL/min when the circle is at the centerof the scale.

Displays the target gas (GAS) flow rate.
Adjust so that the black circle is between
the two vertical bars indicating the upperand lower limits.*
The flow rate will be approximately
300 mL/min when the circle is at thecenter of the scale.

* For more precise measurements, adjust the black circle to the center of the scale.

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4-2. Reference gas calibration procedure
Allow the product to warm up for approximately 5 to 10 minutes after turning on the power before
starting reference gas calibration (see “S.09.-- Reference gas calibration”). Measurement is possible
once reference gas calibration is complete.

4-3. Shutdown procedure
When ending measurement, do not turn off the power while target gas remains inside the product.
Introduce fresh air via GAS IN to clean thoroughly and check to confirm that the measurement reading
returns to zero before turning off the power switch on the product.
For information of how to store the product, refer to “8-1. Procedures for storage or when not in use forextended periods” and “8-2. Procedures for relocation or reuse”.

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4-4. External output signal
The product outputs a 4-20 mA external output signal corresponding to the concentration
measurement.
Output
20 mA

4 mA
Gas
concentration

Output range
Output minimum

Under

Measurement range

Output maximum

Over

A preset special output value is output if an abnormality (FAILURE) is detected by self-diagnosis or
during function checking (FUNCTION CHECK) (mainly in setup mode).
Category

Operation description

Hold last value

Maintains the output value immediately prior to that state.
By default, this setting is used during function checking (FUNCTIONCHECK).

Arbitrary fixed value

Outputs a set 4-20 mA value.
The default setting is 0.5 mA (fixed) for abnormality (FAILURE).

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4-5. Concentration alarms and out of measurement range alarms
The product features three alarm patterns: “H-HH.alarm”, “L-LL.alarm”, and “L-H. alarm”. Each ofthese alarm patterns includes a first alarm setpoint (ALM1) and second alarm setpoint (ALM2) andactivates when the conditions described in the table below are met.
* The alarm patterns that can be set will vary depending on target gas specifications.
Alarm patternFirst alarm condition

Second alarm condition

H-HH. alarm

Measured value ≥ ALM1

Measured value ≥ ALM2

L-LL. alarm

Measured value ≤ ALM1

Measured value ≤ ALM2

L-H. alarm

Measured value ≤ ALM1

Measured value ≥ ALM2

OFF

No alarm

No alarm

When the measured value satisfies the first alarm condition, the first alarm contact activates, and the
ALM1 lamp illuminates. If the measured value no longer satisfies the first alarm condition, the firstalarm contact is reset, and the ALM1 lamp goes out. The second alarm contact operates in the sameway (with default settings).
Category

ScreenState description

First alarm state

The first alarm contact activates, and the
ALM1 lamp illuminates.

Second alarmstate

The second alarm contact activates, and the
ALM2 lamp illuminates.

First alarm andsecond alarmoccur
simultaneously.

The first and second alarm contacts activate,
and the ALM1 and ALM2 lamps illuminate.

* Operation for standard settings

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If the measured value lies significantly outside the measurement range, the product enters theunderscale or overscale state, as described in the table below. The fault contact is activated in thisstate. The 4-20 mA signal is fixed at the upper or lower limit of the measurement range.
Category

ScreenState description

Underscale stateState in which the measured value issignificantly below the lower limit of themeasurement range. The target gas may
contain an unexpected gas, or the zero point
may not have been adjusted correctly.
The fault alarm contact activates, and the
FAULT lamp (orange) illuminates. The 420 mA signal is held at the lower limit value of
4 mA.

Overscale stateState in which the measured value issignificantly above the upper limit of themeasurement range. The target gas may
contain an unexpected gas, or the zero point
may not have been adjusted correctly.
The fault alarm contact activates, and the
FAULT lamp (orange) illuminates. The 420 mA signal is held at the upper limit value of
20 mA.

* Operations for standard settings

CAUTION
Underscale and overscale states are states outside the measurement range of the
product. They indicate normal measurements are not possible. These may also occur
due to incidental effects such as transient noise.
Introduce reference gas into the product to confirm that the product is normal before
continuing the measurement. If you confirm that the zero point is normal, the target gas
may have exceeded the measurement range. Check the conditions at the measurement
point.
Even after the measured value returns to the measurement range, the underscale or overscale state
will be maintained until latching resetting is performed in check mode (see “C.14.-- Display/contact
latching resetting”).

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4-6. Self-diagnostic monitoring function
The product includes self-monitoring and diagnostic functions complying with the NAMUR NE107
standard (self-monitoring and diagnostics of field devices), which enable real-time diagnosis and selfmonitoring of the product state broadly divided into the following four categories.
The following table summarizes the screens displayed for each category together with an explanationof the corresponding product state.
Category

ScreenState description

Abnormal state
FAILURE

State in which an internal or external
abnormality has occurred and themeasurement results and output signal are
not valid.
The fault alarm contact activates, and the
FAULT lamp (orange) illuminates. The 4-20
mA output signal outputs 0.5 mA.

Function checking
FUNCTIONCHECKState in which the product is normal but
measurement was suspended for function
checking operation.
The POWER lamp (green) flashes. The 4-20
mA output signal is fixed at the last output
value.

Outsidespecification
range
OUT OF
SPECIFICATIONState in which the product continues tomeasure normally but conditions outside thespecification range have been detected; themeasurement results and output signal have
low reliability.
The 4-20 mA output signal outputs
measurement results.

MaintenancerequestMAINTENANCEREQUIRED

State in which the product continues tomeasure normally, but some form of
deterioration requiring maintenance has been
detected.
The 4-20 mA output signal outputs
measurement results.

* The lamp indications, contacts, and 4-20 mA output operations in the table are for standard settings.

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4-7. Contacts/display/signal output on returning to normal
A function is included for retaining the LCD screen display and contact states when the state returns tonormal after a state corresponding to one of the categories listed below is detected by self-diagnosis.
These settings can be altered in setup mode.
•

Abnormal state (FAILURE)•

Outside specification range (OUT OF SPECIFICATION)•

Maintenance request (MAINTENANCE REQUIRED)<LCD screen display>
Name

Operation description

TRACE DISP
Trace display

A record of the state that occurred is retained by providing analternating display after the state returns to normal.

AUTO RESET
Auto reset

The display returns to the normal measurement screen after the state
returns to normal.

OFF

No display is provided, even when the set state occurs.

Once a second

Trace display behavior<Contact operation>
Name

Operation description

LATCHING
Self-latching

Retains the contact state even after the state returns to normal.

AUTO RESET
Auto reset

Automatically restores the contact after the state returns to normal.

OFF

No contact operation is performed even when the set state occurs.

38 / 84<4-20 mA signal>
The 4-20 mA signal operates corresponding to the contact state.
Contact state

Operation description

LATCHING
Self-latching

The 4-20 mA signal maintains the preset abnormality detection valueeven after the state returns to normal. The default setting is 0.5 mA(fixed).

AUTO RESET
Auto reset

Automatically restores the 4-20 mA output signal to the measured
value after the state returns to normal.

OFF

No contact operation is performed even when the set state occurs.

* Turning the power off and on clears the retained contact state and trace display operation on the
LCD screen.

4-8. LCD screen display order of priority
Multiple states detected by self-diagnosis will be displayed on the screen in accordance with thefollowing order of priority:
Priority
High

Low

State

Current status

Screen display

FAILURE

Occurring

Displays FAILURE screen.

ALARM

Occurring

FUNCTION CHECK

Occurring

OUT OF SPECIFICATION

Occurring

Only the state with the highest
priority is displayed at the bottom of
the concentration display screen.

MAINTENANCE REQUIRED

Occurring

FAILURE

Trace display

ALARM

Trace display

FUNCTION CHECK

Trace display

OUT OF SPECIFICATION

Trace display

MAINTENANCE REQUIRED

Trace display

Only the state with the highest
priority is displayed alternately atthe bottom of the concentration
display screen.

Check multiple states occurring simultaneously using the following screens in check mode:•

Checking current status: “C.11.-- Status flag checking “DISP. STATUS FLG (CURRENT FLG)””•

Checking trace display: “C.12.-- Status flag checking “DISP. STATUS FLG (TRACE DISP. FLG)””•

Checking contact self-latching: “C.13.-- Status flag checking “DISP. STATUS FLG (RELAY LATCH
FLG)””

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4-9. Switching to other modes
Hold down the MODE key for at least 3 seconds during measurement to display the MODE CHANGE
screen.

At least
3 seconds

Mode change screen

Measuring mode screen

Use the ▲ and ▼ keys to move the cursor (black bar) on this MODE CHANGE screen and select therequired mode, then press the SET key to switch to the selected mode.
The individual mode screens and their details are as follows:
Mode

ScreenDetails

CHECK MODE
Check mode

Mode for displaying and checking the operatingstate of individual units and setting conditions while
continuing measurement.
The 4-20 mA output signal outputs measurement
results in this mode without stopping
measurement.

SETUP MODE
Setup mode

Mode for configuring product settings by the user,
including alarm settings and 4-20 mA output signal
conditions.
Since this mode suspends measurement, you will
be prompted to enter a password.

FACTORY MODE
Factory mode

Mode used for factory adjustment andmaintenance/startup purposes.
This mode is for use by Riken Keiki or qualified
service engineers. It is normally not used by users.
Since this mode suspends measurement, you will
be prompted to enter a password.

MEASURING MODE
Measuring mode

Returns to the normal measuring mode screen.

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==== 5. Check Mode Operating Procedures ============
Check mode is a mode for displaying and checking items such as sensor operating status and productsetting conditions while continuing measurement. The 4-20 mA output signal outputs measurement
results in this mode without stopping measurement.
To enter check mode, select the mode change screen in measuring mode and use the ▲ and ▼ keys
to move the cursor (black bar) to select “CHECK MODE”, then press the SET key to confirm. The
check mode menu screen appears. (See “4-9. Switching to other modes”.)
Hold down the ESC key for at least 3 seconds on the check mode menu screen to return to measuringmode.
At least
3 seconds

Mode change screen

Menu screen

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Measuring mode

5-1. Check mode menu items
The menu items listed in the table below are available in check mode. These are explained in greater
detail on the subsequent pages.

Displays the internalinterferometer sensor
state.

Displays the internal
main controller state.

Displays the 4-20 mA
settings.

Displays the pressure
sensor output.

Displays the temperature
sensor output.

Displays the LCD
display/lamp operation
settings on detecting anabnormal state.

Displays the LCD
display/lamp
operation settings on
detecting an outside
specification range
condition.

Displays the LCD
display/lamp
operation settings on
detecting amaintenance request
condition.

Displays the LCD
display/lamp operation
settings for function
checking.

Displays the LCD
display/lamp operation
settings on detecting a
concentration alarm.

Displays the selfdiagnostic/monitoring
function results.

Displays the selfdiagnostic/monitoring
function results.

Displays the selfdiagnostic/monitoring
function results.

Resets the trace display
and contact self-latchingstate.

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5-2. Items and details
Use the ▲ and ▼ keys to select the item to be checked on the check mode menu screen, then press
the SET key to confirm and display detailed information for that item. This section describes thedetailed information displayed for each item.

C.01.-- Optical sensor state checking “OPTICAL SENSOR UNIT CONDITION”
Sequentially displays optical sensor program information, self-diagnostic results measured within thesensor unit, and other information. Press the SET key on the “OPTICAL SENSOR UNIT CONDITION”
menu screen to display the check screen. Use the ▲ and ▼ keys to select the item to be checked.
Sequentially displays optical sensor unit program information, self-diagnostic results measured within
the unit, and other information.
Displays the program number, SUM
value, Rev number, SPE number, andproduct code.
Menu screen

Displays the interference fringe lightintensity and contrast for LED1 and LED2.

Displays interference fringe phase
information.

Displays the power supply voltage usedby the optical sensor unit, refractive index
measurement results, and LED1/LED2
drive voltages.

Displays self-diagnostic flags managed
within the optical sensor.

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C.02.-- Main controller state checking “MAIN CONTROLLER CONDITION”
Displays main controller program information, self-diagnostic results measured within thecontroller, and other information.
Displays main controller program information, internal self-diagnostic results, and other information.
Press the SET key on the “MAIN CONTROLLER CONDITION” menu screen to display the check
screen. Use the ▲ and ▼ keys to select the item to be checked.
Displays the program number, SUM
value, Rev number, SPE number, andproduct code.
Menu screen
Displays the respective power supply
circuit (3.3 V, 5 V, 24 V) voltages.
Displays the 4-20 mA signal output status.

Displays various self-diagnostic flags
monitored within the main controller.

C.03.-- 4-20 mA setting state checking “4-20mA PARAMETER”
Displays the 4-20 mA output signal output conditions and settings.
Press the SET key on the “4-20mA PARAMETER” menu screen to display the check screen.
Displays the range corresponding to the 4-20 mA output signal within the measurement range, the4-20 mA output signal value output when an abnormal state (FAILURE) is detected, and the 4-20 mA
output signal value output for function checking (FUNCTION CHECK).

Menu screen

Check screen

Output range
4-20 mA setting for abnormal
state
4-20 mA setting for function
checking* If the output value is set to “HOLD”, this means the value immediately prior to the relevant state will
be output.

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C.04.-- Pressure sensor output checking “PRESSURE SENSOR”
Displays the output of the pressure sensor incorporated into the optical sensor unit.
Press the SET key on the “PRESSURE SENSOR” menu screen to display the check screen.
GAS: Output from the fine differential pressure sensor detecting the flow rate of the target gas
supplied to the FI-900
REF: Output from the fine differential pressure sensor detecting the flow rate of the reference gas
supplied to the FI-900
OUT: Output from the absolute pressure sensor for the FI-900 GAS OUT used for pressure correction

Menu screen

Check screen

GAS side differential pressure
sensor output value
REF side differential pressure
sensor output value
OUT side absolute pressure sensor
output value

C.05.-- Temperature sensor output checking “TEMPERATURE SENSOR”
Displays the output of the temperature sensors incorporated into the main controller and opticalsensor unit.
Press the SET key on the “TEMPERATURE SENSOR” menu screen to display the check screen.

Main controller temperature
Optical sensor unit temperature
Menu screen

Check screen

C.06.-- Self-diagnostic output checking “DIAGNOSIS ACTION (FAILURE)”
Displays the LCD display, FAULT lamp (orange), and fault alarm contact operation settings in detailfor individual conditions when an abnormal state (FAILURE) is detected by the selfdiagnostic/monitoring function. No description of this function is provided here because it is intended
for use by Riken Keiki service engineers.

Menu screen

Check screen

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C.07.-- Self-diagnostic output checking “DIAGNOSIS ACTION (OUT OF SPEC.)”
Displays the LCD display operation settings in detail for individual conditions when an outside
specification range condition (OUT OF SPECIFICATION) is detected by the self-diagnostic/monitoring
function. No description of this function is provided here because it is intended for use by Riken Keikiservice engineers.

Menu screen

Check screen

C.08.-- Self-diagnostic output checking “DIAGNOSIS ACTION(MAINTE.REQUIRED)”
Displays the LCD display operation settings in detail for individual conditions when a maintenancerequest (MAINTENANCE REQUIRED) is detected by the self-diagnostic/monitoring function. No
description of this function is provided here because it is intended for use by Riken Keiki service
engineers.

Menu screen

Check screen

C.09.-- Self-diagnostic output checking “DIAGNOSIS ACTION (FUNCTIONCHECK)”
Displays the LCD display operation settings in detail for individual conditions when the product is putin the function checking (FUNCTION CHECK) state by the self-diagnostic/monitoring function. No
description of this function is provided here because it is intended for use by Riken Keiki service
engineers.

Menu screen

Check screen

C.10.-- Self-diagnostic output checking “DIAGNOSIS ACTION (ALARM)”
Displays the LCD display, ALM1 lamp, ALM2 lamp, first alarm contact, and second alarm contact
operation settings when product measurement results satisfy alarm conditions.

Menu screen

Check screen

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C.11.-- Status flag checking “DISP. STATUS FLG (CURRENT FLG)”
Displays detailed information on the current problems identified by the self-diagnostic/monitoring
function.
Press the SET key on the “DISP. STATUS FLG” menu screen to display the check screen. “NO
FLGS.” is displayed if no problems have occurred.

Menu screen

Check screen

When no problems haveoccurred

C.12.-- Status flag checking “DISP. STATUS FLG (TRACE DISP. FLG)”
Displays the details detecting the conditions for performing trace display* identified by the selfdiagnostic/monitoring function. Press the SET key on the “DISP. STATUS FLG” menu screen todisplay the check screen. “NO FLGS.” is displayed if no problems have occurred.

Menu screen

Check screen* Trace display is a function that alternately displays the previously occurring abnormal state screen
and the normal measurement screen to notify the user of past events when the product returns tonormal from an abnormal state. For details of how to reset the trace state, refer to “C.14.-Display/contact latching resetting”.

C.13.-- Status flag checking “DISP. STATUS FLG (RELAY LATCH FLG)”
Displays the details detecting the conditions for performing contact operation self-latching* identified
by the self-diagnostic/monitoring function. Press the SET key on the “DISP. STATUS FLG” menu
screen to display the check screen. “NO FLGS.” is displayed if no problems have occurred.

Menu screen

Check screen* The contact operation self-latching function maintains the contact operation for a product outputting
any kind of event state via a contact operation, even after resetting from the event to normal state.
For details of how to reset contact operation self-latching, refer to “C.14.-- Display/contact latching
resetting”.

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C.14.-- Display/contact latching resetting “LATCHING RESET (DISP. & CONTACT)”This menu item is used to reset the LCD display trace display state and the contact self-latching state.
Press the SET key on the menu screen to display a caution screen indicating that the display screen
and contact latching state will be reset. Review the information shown on the screen, then press the
SET key to reset the display screen, contact self-latching, and LCD display trace state.

Menu screen

Check screen*NOTE
The LCD display and contact activation state will not be reset for current abnormal states.
Refer to “C.11.-- Status flag checking “DISP. STATUS FLG (CURRENT FLG)”” and checkfor current abnormal states.

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==== 6. Setup Mode Operating Procedures ============
Setup mode is used to change the target gas and to configure various settings such as 4-20 mA signal
output conditions and contact operation conditions.
Switching to this mode suspends measurement, and the product switches to the function checking(FUNCTION CHECK) state, enabling the 4-20 mA signal to be fixed at the last output value.
(For details of how to change the output conditions, refer to “S.02.-- 4-20 mA output signal setting“4-20mA SETUP””.)
To enter setup mode, hold down the MODE key for at least 3 seconds while in measuring mode todisplay the mode change screen. Use the ▲ and ▼ keys to select “SETUP MODE”, then press the
SET key to confirm.
A password input screen is then displayed. Use the ▲ and ▼ keys and the SET key to enter the
password one character at a time. The factory default password is set to “00000”.
(For details of how to change the password, refer to “S.22.-- Changing password “CHANGE
PASSWORD””.)
At least
3 seconds

Measuring mode

Password input screen

Mode change screen
Select setup mode using▲ and ▼ keys.

Once the correct password is entered, measurement halts, and a caution screen appears indicatingthat the 4-20 mA output will be fixed. Review the information shown on the screen, then press the SET
key to stop measurement and display the setup mode menu screen.
(Hold down the ESC key for at least 3 seconds on the setup mode menu screen to return to measuringmode.)

Setup mode menu screen

Press ▲ key to update page.

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CAUTIONEntering setup mode and displaying the setup mode menu during a concentration alarmstate (first alarm or second alarm) will reset the concentration alarm state.
Concentration measurement will also be treated as stopped while operations areunderway in setup mode.
This means the status will not change, even if a concentration alarm or abnormal state
occurs.
(* Concentration calculations continue internally.)
If you wish to check concentration values with the contact state and 4-20 mA signal state
fixed and without sending a concentration alarm upstream, use “S.10.-- Offset adjustment“OFFSET SETUP””, “S.11.-- Span adjustment “SPAN SETUP””, or “S.13.-- Measurement
checking “MEASUREMENT READINGS””.
The product will not switch to the concentration alarm state for approximately 15 minutes
after exiting setup mode and switching to the measurement screen, even if theconcentration alarm conditions are met.
The screen will automatically revert to the measurement screen when the product has
been in setup mode for more than 10 hours.

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6-1. Setup mode menu items
The items displayed on the setup mode menu screens are as follows. These are explained in detail on
the subsequent pages.

Target gas selection

4-20 mA output signal
setting

4-20 mA output signal
adjustment

4-20 mA test signal
outputConcentration alarmfunction setting

Concentration alarmfunction test

Contact operation
setting

Contact operation test

Reference calibration

Reading offset
adjustment

Reading sensitivity
adjustment

Reading zero
suppression value
setting

Measurement checking

Product operation
settings for abnormal
condition detection

Product operation
settings for outside
specification range
condition detection

Product operation
settings formaintenance request
condition detection

Product operation
settings for function
checking

Product operation
settings for gas
concentration alarmstate

RS-485/Modbus
communication setting

IrDA communication

Automatic reference
calibration setting

Setup mode
password change

LCD display setting

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6-2. Items and details
S.01.-- Target gas selection “SELECT GAS”
Selects the target gas. Press the SET key on the “SELECT GAS” menu screen to display the currently
selected target gas range. Press the SET key once again to invert the SPE number display.
Use the ▲ and ▼ keys to select the required gas range, then use the SET key to confirm.

Menu screen

Select SPE No. using ▲ and▼ keys.
Press SET key to confirm.

*NOTE
With the standard specifications, only one gas range is registered. The target gas range
cannot be selected.

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S.02.-- 4-20 mA output signal setting “4-20mA SETUP”
Sets the 4-20 mA output signal output conditions.
Display contents

Description of output value

4mA:
0 %LEL20mA: 100 %LEL
FAILURE: 0.50 mA

Measurement for outputting 4 mA in measuring mode
Measurement for outputting 20 mA in measuring mode.
Value output when an abnormal state is detected.* HOLD outputs the value
immediately before abnormal state detection.
Value output for function checking. HOLD outputs the value immediately
before function checking.

F-CHECK: HOLD

Press the SET key on the “4-20mA SETUP” menu screen to display a caution screen indicating theoperations for changing the 4-20 mA signal. Review the information shown on the screen, then press
the SET key to move to the setting change screen. Use the ▲ and ▼ keys to select the condition to
be changed, then press the SET key. The setting details will appear in inverted display. Use the ▲and ▼ keys and the SET key to enter and confirm the new setting.

Menu screen

Use the ▲ and ▼ keys and SET key to enterand confirm the gas concentration for
outputting 4 mA.

Use the ▲ and ▼ keys and SET key to enterand confirm the gas concentration for
outputting 20 mA.
Select whether to fix the last 4-20 mA output
value (HOLD) or set a specified value (0.5 mA
to 22.0 mA) for an abnormality. When settinga specified value, use the ▲ and ▼ keys to
set the value.
Select whether to fix the last 4-20 mA output
value (HOLD) or set a specified value (0.5 mA
to 22.0 mA) for function checking. Whensetting a specified value, use the ▲ and ▼keys to set the value.

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S.03.-- 4-20 mA output signal adjustment “4-20mA ADJUSTMENT”
Adjusts the 4-20 mA output signal output level. Press the SET key on the “4-20mA ADJUSTMENT”
menu screen to display a caution screen indicating that the 4-20 mA signal will be changed. Review
the information shown on the screen, then press the SET key to switch to the test signal output screen
and output a 4 mA or 20 mA test signal.
Press the SET key to invert the respective PWM value display, allowing each output level to be
adjusted. Measure the current using a calibrated tester and use the ▲ and ▼ keys to vary the PWM
values to adjust output levels. Press the SET key to confirm the settings.

Menu screen

4 mA is output.
Use the ▲ and ▼ keys to adjust
precisely to 4 mA.

20 mA is output.
Use the ▲ and ▼ keys to adjust
precisely to 20 mA.

CAUTION
When adjusting 4-20 mA output values on this screen, make sure the ammeter or other
tester remains connected. If the tester is disconnected, the disconnection detection
function will activate, and adjustment may not be completed normally.
Press the ESC key to exit the output test and return to the menu screen. The 4-20 mA output values
will revert to the values before adjustment.

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S.04.-- 4-20 mA output test “4-20mA TEST”
Adjusts the 4-20 mA output signal to output an arbitrary test signal. Press the SET key on the “4-20mA
TEST” menu screen to display a caution screen indicating that the 4-20 mA output signal will bechanged. Review the information shown on the screen, then press the SET key to switch to the test
signal output screen and output a 4 mA test signal.
Press the SET key once again to invert the output value display. Use the ▲ and ▼ keys to change thetest signal within the range from 0.50 mA to 22.00 mA in 0.05 mA steps.

Menu screen

The test signal can be changed to a value
within the range from 0.50 mA to 22.00 mA.

Press the ESC key to exit the output test and return to the menu screen. The 4-20 mA output values
will revert to the values before output testing.

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S.05.-- Concentration alarm function setting “ALARM SETUP”
Sets the concentration alarm function. Press the SET key on the “ALARM SETUP” menu screen todisplay the current alarm function settings. Pressing the SET key once again will cause the settings toblink. Use the ▲ and ▼ keys to change the settings.
Alarm type

Description

H-HH.

Issues alarm when the concentration reading exceeds the ALM1 and ALM2
values.
Issues alarm when the concentration reading falls below ALM1 or exceeds
ALM2.

L-H.

L-LL.
OFF

Issues alarm when the concentration reading falls below the ALM1 andALM2 values.
No alarms are issued.

Select the alarm type.
Menu screen

Edit the first alarm setpoint (ALM1)
setting.

Edit the second alarm setpoint (ALM2)
setting.

Edit the alarm delay time.

*NOTE
Set the alarm setpoints after taking into account factors such as measurement accuracy andenvironmental effects. We do not recommend setting the setpoints to values lower than 10 %or greater than 90 % of the measurement range.

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S.06.-- Alarm test “ALARM TEST”
Tests the concentration alarm function. This screen allows the 4-20 mA output signal to be changed.
The contacts will also activate, depending on the concentration.
Press the SET key on the “ALARM TEST” menu screen to display a caution screen. Review the
information shown on the screen, then press the SET key to switch to the concentration alarm function
test screen and output a simulated gas concentration measurement result signal.
Use the ▲ and ▼ keys to change the simulated gas concentration measurement result signal. The
first alarm and second alarm contacts activate when the simulated gas concentration measurement
result signal satisfies the respective first and second alarm conditions.

Menu screen

Concentration alarmfunction test screen

Change the simulated gas
concentration measurement result
signal.
This can be adjusted across therange from underscale to overscale.

The first alarm contact activateswhen the simulated gas
concentration measurement result
signal is changed to a value thatsatisfies the first alarm condition(ALM1).
The second alarm contact activateswhen the simulated gas
concentration measurement result
signal is changed to a value thatsatisfies the second alarm condition(ALM2).

*NOTE
The alarm test screen can be used to simulate operation for measurements in the range
from underscale (approximately -10 %) to overscale (approximately +10 %). The out-ofscale lock function may activate if a value is changed beyond the underscale or overscalevalue.
If this occurs, press the SET key to reset the out-of-scale lock state or the ESC key to returnto the menu screen.

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S.07.-- Contact energization setting “CONTACT SETUP”
Sets the operations (always energized or always de-energized) for the contacts used by the product.
No description of this function is provided here because it is intended for use by Riken Keiki service
engineers.

This can be set to DE-ENERGIZED or
ENERGIZED.

S.08.-- Contact operation checking “CONTACT TEST”
Outputs a normal/active state test signal for testing the contact operations used by the product. No
description of this function is provided here because it is intended for use by Riken Keiki service
engineers.

This can be set to NORMAL or
ACTIVE.

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S.09.-- Reference gas calibration “REF.CALIBRATION”
Performs reference gas calibration. Press the SET key on the “REF.CALIBRATION” menu screen todisplay the “REF.CALIB.” standby screen. Press the SET key once again to perform reference gas
calibration.

CAUTION
Reference gas calibration requires adequate flow of the reference gas via the target
gas IN inlet.

Ensure adequate flow of the reference gas via the target gas IN inlet in this state. Check the
PHASE θALL value. Reference gas calibration is not required if the PHASE θALL value is close
to 0 (e.g., within ±0.0100).
To perform reference gas calibration, use the ▲ and ▼ keys to select “REF.CALIB.”, then press
the SET key to confirm.

*** This is displayed only if an external solenoid valve contact (optional function) is used.

The display returns to the check screen once calibration ends. Check to confirm that the PHASE
θALL value is close to 0 (e.g., within ±0.0100).
To exit the operation, press the ESC key or select “CANCEL”.

*NOTE
The function used to control an external solenoid valve to introduce reference gas in coordination withthe product main unit operation is an optional function. This must be designed in conjunction with thesampling system, so contact Riken Keiki for information.

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S.10.-- Offset adjustment “OFFSET SETUP”
Performs offset adjustment on the measurement results. No explanation of this procedure is provided
here because it is performed only by Riken Keiki service engineers.

S.11.-- Span adjustment “SPAN SETUP”
Performs span adjustment on the measurement results. No explanation of this procedure is provided
here because it is performed only by Riken Keiki service engineers.

S.12.-- Suppression adjustment “SUPPRESS SETUP”
Sets upper and lower display limits for measurement results. No explanation of this procedure isprovided here because it is performed only by Riken Keiki service engineers.

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S.13.-- Measurement checking “MEASUREMENT READINGS”
Displays various internal sensor data. No description of this function is provided here because it isintended for use by Riken Keiki service engineers when checking product operation and during
maintenance.
D: Same as displayed on themeasurement screen
DS: Internally calculated value

Nn (+), Nn (-): Refractive index
Nc (+), Nc (-): Refractive index (before
correction)
θALL (+), θALL (-): Total phase

Temperature, absolute pressure,differential pressure, 4-20 mA detection
value

S.14.-- Self-diagnostic operation (abnormality) “DIAGNOSIS ACTION (FAILURE)”
Sets the LCD display and contact operations in detail for individual conditions when an abnormal state(FAILURE) is detected by the self-diagnostic/monitoring function. No description of this function isprovided here because it is intended for use by Riken Keiki service engineers.
DISPLAY: OFF, AUTO RESET, TRACEDISP
ACTION: OFF, AUTO RESET, LATCHING
POS.: (F), (S), (C), (M), (AL1), (AL2), OFF* F is the fault contact, and AL1/AL2 are
the alarm contacts.

S.15.-- Self-diagnostic operation (outside specification range) “DIAGNOSISACTION (OUT OF SPEC)”
Sets the LCD display and LED lamp actions in detail for individual conditions when an outside
specification range condition (OUT OF SPECIFICATION) is detected by the self-diagnostic/monitoring
function. No description of this function is provided here because it is intended for use by Riken Keikiservice engineers.
DISPLAY: OFF, AUTO RESET, TRACEDISP
ACTION: OFF, AUTO RESET, LATCHING
POS.: (F), (S), (C), (M), (AL1), (AL2), OFF* F is the fault contact, and AL1/AL2 are
the alarm contacts.

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S.16.-- Self-diagnostic operation (maintenance request) “DIAGNOSIS ACTION(MAINTE.REQUIRED)”
Sets the LCD display and LED lamp operations in detail for individual conditions when a maintenancerequest (MAINTENANCE REQUIRED) is detected by the self-diagnostic/monitoring function. No
description of this function is provided here because it is intended for use by Riken Keiki service
engineers.
DISPLAY: OFF, AUTO RESET, TRACEDISP
ACTION: OFF, AUTO RESET, LATCHING
POS.: (F), (S), (C), (M), (AL1), (AL2), OFF* F is the fault contact, and AL1/AL2 are
the alarm contacts.

S.17.-- Self-diagnostic operation (function checking) “DIAGNOSIS ACTION(FUNCTION CHECK)”
Sets the LCD display and LED lamp operations in detail for individual conditions when the FI-900 is in
the function checking (FUNCTION CHECK) state. No description of this function is provided here
because it is intended for use by Riken Keiki service engineers.
DISPLAY: OFF, AUTO RESET, TRACEDISP
ACTION: OFF, AUTO RESET, LATCHING
POS.: (F), (S), (C), (M), (AL1), (AL2), OFF* F is the fault contact, and AL1/AL2 are
the alarm contacts.

S.18.-- Self-diagnostic action (concentration alarm) “DIAGNOSIS ACTION(ALARM)”
Sets the LCD display and contact operations in detail for individual conditions when the measurement
results satisfy the concentration alarm conditions.
No description of this function is provided here because it is intended for use by Riken Keiki service
engineers.
DISPLAY: OFF, AUTO RESET, TRACEDISP
ACTION: OFF, AUTO RESET, LATCHING
POS.: (F), (S), (C), (M), (AL1), (AL2), OFF* F is the fault contact, and AL1/AL2 are
the alarm contacts.

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S.19.-- RS-485 communication setting “RS-485/MODBUS SETUP”
Allows editing of RS-485 (Modbus) communication settings. Press the SET key on the “RS-485/
MODBUS” menu screen to display the individual setting items. Use the ▲ and ▼ keys to select theitem to be edited, then press the SET key to confirm. This function is intended for use by Riken Keikiservice engineers.

*NOTE
The RS-485 (Modbus) communication function is an optional function. For details of information suchas communication specifications and address maps, contact Riken Keiki.

*NOTE
If multiple devices are connected on the same line, each device must have a unique slave ID.

The setting ranges for the individual setting items are as follows:
SLAVE ID: 1 to 247
TRANSMIT: RTU mode, ASCII mode
BAUD RATE: 4800, 9600, 19200, 38400, 57600, 115200 bps
DATA BIT: 7-bit, 8-bit
STOP BIT: 1-bit, 2-bit, NONE
PARITY BIT: NONE, IGNORE, EVEN, ODD
SEND WAIT1 (fixed value): Time for sending 8 to 127 characters
SEND WAIT2 (random value): Time for sending 8 to 127 characters

Displays the total message received count.
Displays the CRC error count.
Displays the exception error count.
Displays the corresponding message received count.

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Displays the no-response/response count.
Displays the NAK/response count.
Displays the BUSY/response count.
Displays the overrun count.
Self-diagnostic counter values described in the Modbus serial
communication specifications can be cleared. Select “OK”, then holddown the SET key for at least 3 seconds to clear all counter values.
Sets the address map to the default.

CAUTION
This operation may prevent normal communication.
Avoid this operation. It is intended for use by Riken Keiki service
engineers.

S.20.-- IrDA communication “IrDA COMMUNICATION”
Downloads log data stored internally via IrDA communication.
Press the SET key on the “IrDA COMMUNICATION” menu screen to display the individual operation
items.
Use the ▲ and ▼ keys to select the required operation item, then press the SET key to move to thecorresponding execution screen.

Menu screen

Start screen

Start screen

Communication start

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A warning appears if other processing
is currently underway. Wait for a while
before restarting.

Communicating

S.21.-- Automatic reference calibration setting “AUTO REF.CAL SETUP”
Automatic reference calibration is a function that uses a built-in timer to automatically performreference calibration at preset intervals. No description of this function is provided here because it isintended for use by Riken Keiki service engineers.

*NOTE
Automatic reference calibration is an optional function. A solenoid valve must be included on theboard, and a pipe system must be configured to enable reference gas to be introduced via the targetGAS IN inlet. Additionally, the second alarm will become unavailable, as the second alarm contact isused as a solenoid valve contact.
For detailed information, contact Riken Keiki.

Screen when automatic reference calibration function cannot be set

Sets the automatic reference calibration cycle.
OFF (auto calibration disabled), 3H (3-hour cycle), 6H (6-hour cycle),
12H (12-hour cycle), 24H (24-hour cycle), 2D (2-day cycle),
7D (7-day cycle), 28D (28-day cycle)
Sets the reference gas suction time and target gas suction time forreference calibration.
* The reference gas suction time required will differ depending on thetarget gas type and external pipe system. This must be set after
checking the time required for the reference gas to stabilize well after
being introduced.
Perform reference gas calibration if the automatic reference calibration
function settings have been changed on this setup screen.
* Performing reference calibration starts the timer determining theoperation cycle.
If reference gas calibration is not performed, the timer will not
activate, and automatic calibration will not be performed.

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The reference gas calibration operation when the automatic reference calibration is enabled is asfollows.

Screentransition
Contact is activated.

Contact
operation*1
Operatingtime*2

Reference gas suction time

About 2 seconds

Contact is restored.

Measurement gas
suction time

*1. For the excitation and de-excitation of the contact, follow the setting item "CONTACT2" in“S.07. CONTACT SETUP".
*2. The reference gas aspiration time and measurement gas aspiration time are common time
settings. This setting can be changed from 0 to 1800 seconds (in 1-second increments) in setting
item "TIME" in "S.21. AUTO REF. CAL SETUP". If you set it to 0 seconds, it will not work.

S.22.-- Changing password “CHANGE PASSWORD”
This allows you to change the password required to enter setup mode. Press the SET key on the“CHANGE PASSWORD” menu screen to display the password check screen showing the currently
set password.
Press the SET key once again to switch to the password entry screen. Use the ▲ and ▼ keys andSET key to enter alphanumeric characters (0 to 9 and A to F) one character at a time.

Menu screen

Use the ▲ and ▼ keys toenter one character at atime, then press the SET
key to confirm.

CAUTION
Note that you will not be able to enter setup mode if you forget the password set.
If you forget the password, contact Riken Keiki.

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==== 7. Maintenance ==============================The product is designed to operate continuously over extended periods of time. Periodic
maintenance is required to ensure sufficient performance over this period.

<Maintenance services>
Riken Keiki provides services related to regular maintenance, adjustment, and servicing. Our certified
service engineers have expert knowledge of the dedicated tools used for these services, along withexpertise in products. We recommend taking advantage of our maintenance service to ensure safeuse of the product.

7-1. Maintenance intervals and items
Maintenance consists of daily and monthly maintenance performed by the user and six month
maintenance carried out every six months by Riken Keiki.

7-2. Daily maintenance
Daily maintenance consists of inspections to confirm the integrity of product operations. Inspect the
product in accordance with the maintenance items and assessment criteria shown in the following
table.

①②③

Maintenance item
① POWER lamp

② Event lamps③ LCD display④ Target gas (GAS) flow rate
Reference gas (REF) flowrate④
Assessment
The POWER lamp should illuminate continuously when the
product is normal. Check to confirm that it is illuminatednormally.
The event lamps should be off continuously when the product isnormal. Check to confirm that the lamps are not illuminated.
Check to confirm that indications such as abnormal state(FAILURE), outside specification range (OUT OF
SPECIFICATION), maintenance request (MAINTENANCEREQUIRED) are not displayed.
Check to confirm that the black circles indicating the target gas(GAS) flow rate and reference gas (REF) flow rate are both
between the two vertical bars corresponding to the upper andlower limits.

If any abnormality is found, investigate and take appropriate action as described in Troubleshooting.
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7-3. Monthly maintenance
Monthly maintenance consists of inspections to confirm the integrity of the product explosion-proof
performance. Inspect the product in accordance with the maintenance items and assessment

criteria shown in the following table.
Maintenance item

Assessment① Cast casing

Check to confirm that the casing is normal and free of damage.

② Fastening screws and bolts

Check to confirm that the fastening screws and bolts are notloose or missing.

③ Explosion-proof certification
plate

Check to confirm that the plate printed with the type examination
certificate marking is normal and correct.

④ Transparent window

Check to confirm that the transparent window is not cracked,
discolored, or deformed.

⑤ Grounding terminal

Check to confirm that the grounding cable is correctly connectedto the grounding terminal.

⑥ Cable glands, wiring

Check to confirm that the cable glands and wiring is problemfree.

①
②

④

③

⑥
⑤

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7-4. Six month maintenanceSix month maintenance consists of inspections to confirm the integrity of items such as sensor output,
power supply voltage, contacts, and analog signal output. The following items are carried out asnecessary.
① Product cleaning④ Reading operation check② Parts replacement⑤ Other③ External pipe component replacement

The items indicated for daily maintenance must also be carried out during the six month maintenance.

7-5. Recommended periodic replacement parts
Mean ambient temperature

Recommended periodic
replacement parts

Replacement
intervalLess than 50 °C

None

-

50 °C or morePower supply terminal plate unit

5 years

The product has a design life of 10 years.
The filters used with the sampling system should be replaced at appropriate intervals.

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==== 8. Storage, Relocation, and Disposal =============
8-1. Procedures for storage or when not in use for extended periods
If the product is not in use for extended periods with the pipes and cables from the FI-900 andsampling system still connected, turn off the power and shut off the target gas and reference gas
supplies. If there is a possibility of gas entering via the OUT side, take appropriate measures, such as
disconnecting the OUT side pipes.
If the product is stored for extended periods (e.g., in a warehouse), it should be stored in a location at
normal temperature and humidity, and away from direct sunlight. Store the FI-900 main unit with thefront cover closed to avoid damage to the explosion-proof bonding surfaces.

8-2. Procedures for relocation or reuse
When resuming operation after reconnecting pipes and cables, contact a service agent appointed by
Riken Keiki to request the relevant startup work. In cases where only the power supply and target
gas/reference gas supply needs to be restarted, contact a service agent appointed by Riken Keiki asnecessary to request the relevant work.

8-3. Product disposal
Dispose of the product appropriately as industrial waste (incombustible) in accordance with local
regulations. The main controller PCB inside the main unit contains the following coin-type battery. Thisshould be removed before disposing of the product.
Coin-type lithium manganese dioxide battery specifications
Product code:
Nominal voltage:
Standard capacity:

CR12203V
36 mAhRemoval method
Remove the main controller unit. The battery is
contained behind the part indicated in the diagram on
the right. The battery is covered by the plastic case. The
plastic case is attached to the PCB, and so should be
removed using pliers or a screwdriver. Remove thebattery by sliding it out sideways. Wrap the removed
battery in insulating tape before disposing.

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Battery is located behind here.

==== 9. Troubleshooting ==========================The material provided here is intended for investigating the causes of problems by determining thestate of the product from the details displayed on the main unit. While it describes as many likely
symptoms as possible, it does not include every possible symptom. If the cause of a problem cannot
be determined from the material provided here, contact Riken Keiki.

9-1. Abnormality <FAILURE>

Display

State description

Main causes and corrective action

Main controller ROM fault

The main controller ROM is faulty.
The main controller must be replaced.

Main controller RAM fault

The main controller RAM is faulty.
The main controller must be replaced.

Main controller FRAM fault The main controller FRAM is faulty.
The main controller must be replaced.

Abnormal temperaturedetected in main controller

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If there is no problem in the installation
environment, the main controller may be
defective.

Display

State description

Main causes and corrective action

Supply power abnormality
detected in main controller

If there is no problem with the power supply tothe product, the power supply terminal plate
unit or main controller may be defective.

Sensor abnormality
detected in main controller

The cable connecting the sensor to the main
controller or the sensor may be defective.

4-20 mA output signal
abnormality detected inmain controller

If there is no problem such as disconnection of
the 4-20 mA cable, the power supply terminal
plate unit or main controller may be defective.

ROM abnormality
detected in sensor

The sensor ROM is faulty.
The sensor must be replaced.

RAM abnormality detected
in sensor

The sensor RAM is faulty.
The sensor must be replaced.

FRAM abnormality
detected in sensor

The sensor FRAM is faulty.
The sensor must be replaced.

Temperature abnormality
detected in sensor

If there is no problem in the installation
environment, the sensor may be defective.

Abnormal GAS OUT
absolute pressure
detected in sensor

If there is no problem such as blockage in thegas suction inlet or pipes, the sensor may be
defective.

Supply power abnormality
detected in sensor

If there is no problem with the power supply tothe product, the power supply terminal plate
unit or sensor may be defective.

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Display

State description

Main causes and corrective action

Abnormal light intensity drop ininterference fringe image datadetected in sensor

The sensor may be damaged due toforeign matter being sucked in.

Abnormal contrast drop ininterference fringe image datadetected in sensor

The sensor may be damaged due toforeign matter being sucked in.

Reference gas flow rateabnormality detected in sensor

The supply rate may be too low, too high,or passages inside the product may beblocked or leaking.

Target gas flow rate abnormality
detected in sensor

The supply rate may be too low, too high,or passages inside the product may beblocked or leaking.

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9-2. Outside specification range <OUT OF SPECIFICATION>

Display

State description

Main causes and corrective action

Target gas flow rate outside specified
range detected in sensor

Adjust the gas flow rate towithin the specified range.

Reference gas flow rate outside specified
range detected in sensor

Adjust the reference gas flowrate to within the specified
range.

Sudden fluctuations in GAS OUT
absolute pressure detected in sensor

There may be a suction
abnormality due to suddenpressure fluctuations inside thetest chamber or due to blockageof the gas suction inlet.

GAS OUT absolute pressure outside
specified range detected in sensor

The gas suction inlet may beblocked or the internal filter may
be clogged.

Sudden temperature fluctuations detected
in sensor

The sensor usage environment
needs to be reassessed.

Temperature outside specification range
detected in sensor

The sensor usage environment
needs to be reassessed.

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Display

State description

Main causes and corrective action

Concentration outside specification range
detected

Check to confirm that theconditions indicated in theTarget Gas Specifications are
satisfied.

Faulty 4-20 mA signal output detected inmain controller

Check to confirm that the usage
method satisfies the cableconnection/load resistance(max. 300 Ω) conditions.
Short-circuit the output
terminals if the 4-20 mA output
is not used.

Power supply outside specified range
detected in main controller

Check to confirm that the power
supply provided satisfies therequired specifications.

Temperature outside specification range
detected in main controller

The product usage environment
needs to be reassessed.

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9-3. Maintenance request <MAINTENANCE REQUIRED>

Display

State description

Main causes and corrective action

Abnormality detected in RS-485
communication settings

RS-485 communication must
be reset.

Drift within permitted range detected insensorPerform reference gas
calibration(REF.CALIBRATION).

Interference fringe contrast drop within
permitted range detected in sensor

The optical sensor inside thesensor unit is becoming
progressively dirty or degraded.
The sensor must be replaced.

Interference fringe light intensity drop
within permitted range detected insensor.

The optical sensor inside thesensor unit is becoming
progressively dirty or degraded.
The sensor must be replaced.

Sensor mismatch between chamber
length and gas specifications

Wrong combination of
measurement gas and opticalsensor unit. It is necessary toreplace the optical sensor unit
with an optical sensor unit of
the correct chamber length.

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9-4. Function checking <FUNCTION CHECK>

Display

State description

Main causes and corrective action

State in which function checking is
active using external communication

This display does not appear
with standard specifications.

Automatic reference calibration (optional
function) underway

This display does not appear
with standard specifications.

Warm-up underway

This display does not appear
with standard specifications.

Check reference gas (optional function)
underway

This display does not occur
under normal specifications.

*NOTE
The 4-20 mA output is linked to the reading only during FUNCTION CHECK warm-up.
The warm-up function is designed to perform 4-20 mA output operations differing from other function
checks in order to restore the 4-20 mA output value as quickly as possible after temporary power cutouts due to momentary power failures.

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9-5. Concentration alarm <ALARM>

Display

State description

Main causes and corrective action

State in which the measured value
greatly exceeds the upper limit of themeasurement range

If this is not reset by
performing reference gas
calibration, check the targetgas.

State in which the measured value isgreatly below the lower limit of themeasurement range

If this is not reset by
performing reference gas
calibration, check the targetgas.

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9-6. Caution display <CAUTION>
A caution screen is displayed as a cautionary warning if measurement is stopped and the 4-20 mA
output signal and contact signal are fixed or changed to values that differ from the measurement state.
Selecting “OK” and continuing with the subsequent processing will change the output signal.
Display

Main causes and corrective action
Displayed before resetting the LCD screen and contact hold state

Displayed before stopping measurement and fixing to a specified output
value when entering setup mode

Displayed when the signal output will differ from the specified value insetup mode

Displayed when the contact will differ from the contact state fixed whenmeasurement is stopped in setup mode

The following displays may appear when operating in setup mode.
Display

Main causes and corrective action
Screen displayed when data differing greatly from the previous results is
detected after performing “S.09.-- Reference gas calibration” in setup
mode
Sufficient reference gas may not be flowing in via the FI-900 GAS IN inlet.
Thoroughly check to confirm that the operations and procedures arecorrect before selecting “OK”.
Note that if this screen appears frequently, the optical sensor unit or
sampling system may be defective.
Screen displayed when the 4-20 mA output circuit is detected as open
after performing “S.03.-- 4-20 mA output signal adjustment” in setup mode
Adjust with the 4-20 mA output circuit connected.
Note that if this screen appears frequently, the main controller unit or
terminal plate unit may be defective.
Displayed when writing setting information to the FRAM fails after
modifying the settings in setup mode. If writing fails repeatedly or
frequently, the main controller may be defective.

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Displayed when the power required for writing setting information to the
FRAM is not provided after modifying the settings in setup mode. If noproblem is identified in the power supply fed to the FI-900, the power
supply terminal plate unit or main controller may be defective.
Screen that may appear only under special work conditions such as FI900 manufacturing processes

9-7. Other displays
Display

Main causes and corrective action
The left screen will be displayed if an incorrect password is entered when
prompted to enter setup mode.
Press the SET key or ESC key to perform the procedure to enter setup
mode again.

9-8. Unrelated to screen display
Display
The power
cannot be
turned on.
Nothing isdisplayed.

Main causes

Corrective action

The power switch is turned off.

Turn on the power switch.

A fuse has blown.

Check the fuse and replace with a rated
fuse if it has blown.

Power supply circuit
abnormality/instantaneousinterruption

Check the power supply voltage.
Make sure the power is supplied at the
rated voltage.
Take the appropriate action such as
reassessing/adding an uninterruptible
power supply, power supply line filter, andinsulated transformer.

Internal connector cableabnormality(disconnected/unconnected/shortcircuit)

Check the internal cables for coming off,crushing, damage, short-circuit, etc.
If there are abnormalities with the flat
cable, the main unit will need to be
replaced. Contact Riken Keiki.
If there are abnormalities with a cableconnecting to the terminal plate, takeappropriate action such as reconnecting.

External connector cableabnormality(disconnected/unconnected/shortcircuit)

Check the external cables for coming off,crushing, damage, short-circuit, etc.
If there are abnormalities with a cable,
take appropriate action such as cablereplacement.

80 / 84

==== 10. Product Specifications =====================
10-1. Standard specifications
Model
Measuring principle
Target gas
Measurement range
Alarm setpoints
Measurement
accuracy
Response time
Measuring method

FI-900
Optical interferometric method
Refer to the separate “Target Gas Specifications”.
Refer to the separate “Target Gas Specifications”.
Depending on the measuring gas.
F.S. ±3 % (Under identical conditions, refer to the separate “Target Gas
Specifications”.)
T90 within 30 s (Refer to the separate “Target Gas Specifications”.)
Gas introduction at prescribed flow rate from external sampling system

Prescribed flow rate

Measuring gas flow rate：300mL/min
Reference gas flow rate：10mL/min

Display function
External output
Communication
output
Maintenance output
First alarm contacts
Second alarm contacts
Fault alarm contacts
Self-diagnostic
function
Power source
Power consumption

Recommended
cablesWarm-up time
Protection level
Operatingtemperature range
Operating humidity
range
Operating pressure
range

Full-dot LCD (with backlight) concentration readout/maintenanceindications, LED lamp status indications
4 mA to 20 mA DC (insulated, current discharge type), maximum
permissible load resistance 300 Ω
RS-485 Modbus output function (option)
IrDA communication
No-voltage contact; contact capacity 1 A, 30 V DC (resistance load)
No-voltage contact; contact capacity 1 A, 30 V DC (resistance load)
No-voltage contact; contact capacity 1 A, 30 V DC (resistance load)
Reduced light intensity, reduced contrast, air pressure abnormality,
temperature abnormality, reduced flow rate, etc.
100 V to 240 V AC ±10 %, 50/60 Hz / 24 V DC ±10 %* DC power supply only for ATEX/IECEx/UKEX spec.
Max. 20 VA (100 V to 240 V AC ±10 %, 50/60 Hz) / Max. 6 W (24 V DC
±10 %)* DC power supply only for ATEX/IECEx/UKEX spec.
Output cable:
CVVS or similar shielded cable (1.25 mm2 or
2 mm2)/2-coreCommunication cable: KPEVS or similar shielded twisted-pair cable(0.75 mm2)/2 pairs
Contact cable:
CVVS or similar shielded cable (1.25 mm2 or
6 mm2)/2- to 6-core
AC Power cable:
CVV or similar cable (1.25 mm2 or 2 mm2)/2- or 3core
DC Power cable:
CVVS or similar cable (1.25 mm2 or 2 mm2)/2- or 3core
Initial: Approx. 5 seconds
No warm-up time (Refer to the separate “Target Gas Specifications”.)
Equivalent to IP 66/67
Japan Ex spec.: -20 °C to +57 °C (no sudden changes)
IECEx/ATEX/UKEX spec.: -20 °C to +60 °C (no sudden changes)
Not exceeding 95 %RH (no condensation/liquefaction of gas insideproduct)
Atmospheric pressure (with no surging)81 / 84

Target gas
temperature
External dimensions
WeightExplosion-proof
construction
Explosion-proof
class
Explosion-proof
certification number

Self-diagnostic
function

Other functions

Equal to ambient temperature at GAS IN on main unit
(no condensation/liquefaction of gas inside product)
Approx. 286 mm (W) × 453 mm (H) × 150 mm (D) (excluding projections)
Approx. 23 kg
Flame-proof enclosure
Japan Ex: Ex d II B+H2 T4: Ex d IIB+H2 T4 Gb
IECEx: II 2G Ex db IIB+H2 T4 Gb
ATEX/UKEXJapan Ex: TC21460
IECEx: IECExDEK12.0058X
ATEX: DEKRA12ATEX0187X
UKEX: DEKRA21UKEX0365X
Status monitoring in four categories• Abnormality (FAILURE)• Function checking (FUNCTION CHECK)• Maintenance request (MAINTENANCE REQUIRED)• Outside specification range (OUT OF SPECIFICATION)• Ambient temperature and atmospheric pressure correction functions(depending on target gas specifications)• Flow rate display function (on target gas side, reference gas side)• Automatic light intensity adjustment function• Zero suppression function (standard: OFF, settable)

CAUTION
The product interior temperature will be even higher than the ambient temperature whenused in ambient temperatures around 50 °C. Avoid using the product in environments
where the temperature may rise to 50 °C or higher at any hour of day or night, as thismay negatively affect the product life.

82 / 8410-2. Detection principle
The refractive index of a gas mixture is determined by the types and mixing ratios of different gases
contained within it. If a gas mixture consists of two known gas types, their mixing ratios(concentrations) can be determined by measuring the refractive index.
The optical interferometric sensor used in this product forms an interference fringe image on theimage sensor, with these fringes moving proportionally with variations in refractive index. This
interference fringe image is recorded by the image sensor and subjected to phase analysis todetermine the interference fringe displacement with a high degree of precision, which is thenconverted to the refractive index.
Concentrations of various gas mixtures can be displayed by calculating data such as types of target
gas and base gas making up the gas mixture and the precise refractive index obtained.
The sensitivity of the optical interferometric sensor is determined by the length of the chamber throughwhich the gas flows. As the chamber length is unvarying, a high degree of precision can be maintained
over extended periods.
Prism

Chamber

Parallel plane mirrors

Lens

Image sensor

LED light source

MirrorHalf mirror

LED light source

Schematic diagram of an optical interferometric sensor

83 / 84

==== 11. Terminology =============================
Definitions of terminology used in this manual
Lower
explosive limit

The minimum concentration of a combustible gas mixed in air at which ignition
will result in explosion%LEL

The concentration of a combustible gas expressed as a percentage of the lower
explosive limit of the combustible gas

vol%

The concentration of gases in units of parts per 100 by volume

GroundingConnect the grounding terminal of the product to a specified facility to prevent
electric shock.

Target gas

The gas to be measured within the sample gas

Base gas

The remaining gas in the sample gas excluding the target gas. The productnormally takes measurements in air. The base gas for the product will normallybe air (fresh atmosphere).

Reference gas

Gas used as datum (refractive index datum) for concentration measurements
The product normally uses the base gas as the reference gas. The reference
gas for the product will normally be air (fresh atmosphere).

84 / 84

Revision history
Issue

RevisionIssue date

0First issue

6/15/2020

1Standardize words「analyzer → monitor」/ Error correction
Addition「10-1. Standard specifications: Specified flow」
Correction「1-6-2. Technical data: Applicable Standards」, Declaration ofconformity

7/13/2020

2

Correction Safety information, Declaration of conformity

8/21/2020

3

Correction「9. Troubleshooting」

9/25/2020

4

Addition「S.21.-- Automatic reference calibration setting “AUTO REF.CAL
SETUP”」

3/10/2021

5

Declaration of conformity

11/12/2021

6

Addition「UKEX specification」, Correction CE Declaration of conformity,
Addition UKCA Declaration of conformity

10/12/2023