PC3E-0430

Tough ＆Smart！

Equipped with a high-reliability optical interferometric sensor
SUS used for gas contact parts(able to handle corrosive gases)

Enhanced self-diagnostic function(compatible with MODBUS communications)

Easier maintenance

For Controlling and Measuring
Gas Concentrations

Optical Interferometric
Gas Monitor
Model FI-900
ATEX
IECEx
TIIS(Japan Ex)
CE Marking

Enhanced functionality and performance for lower customer
operation and management burden!

Tough
Equipped with a high-reliability optical interferometric sensor
Measurement principle:
The gas concentration is detected from the amount of movementof interference fringes that occur due to the difference in therefractive indexes of the sample gas and reference gas.
Features: almost no degradation of sensor sensitivity.
Even if the light source level drops, there is no change inthe positions of interference fringes.
= no change in sensor sensitivity.
Interference fringes undernormal conditions

Interference fringes with drop in lightsource level (illustration)

History of optical interferometric gas monitors• SUS used for gas contact parts• Enhanced self-diagnostic function• Complies with international
explosion-proof regulations• Digital display

Model FI-900• Uses Fourier transform
analysis method

2020• Uses LED light source• Equipped with CCD camera

No change in interference fringes
positions even with less light level

Model FI-800
2005• Smaller and lighter weightThis design differs from ordinary optical sensors as it isless susceptible to decreases in light source level or a dirty
chamber, and as there is no change in the sensitivity, it isa high-reliability sensor.

• Sales grow after
being recognized
for reliability

Riken gas detector
Model 18

SUS used for gas contact parts

1952(able to handle corrosive gases)
SUS is used for gas contact parts, which means it can beused for explosion prevention for NH3 and high-concentration hydrogen that the previous unit was not capable of.
(SUS specifications for sensor part available as an option)

Smart
Enhanced self-diagnostic function

Riken gas detector
Model 31930

Played an important role following frequent
explosions on oil tankers in the 1930s.

Table Self-diagnostic monitoring parameters (excerpt)(compatible with MODBUS communications)
The FI-900 has enhanced self-diagnostic functions toconstantly monitor self-diagnostic parameters like the 10
items shown in the table on the right, while diagnosing
operating conditions of the device or its usage environment.
It is compatible with MODBUS communications toconstantly monitor not only gas concentrations but also thestate of the measurement device. Log data is also recordedon the measurement device, and can be checked to identify
causes quickly on site if faults occur with the device.

In this era, gasconcentration was visuallychecked by observing the scale.

Sensor output
Sensor temperature
GAS flow rate
REF.GAS flow rateGAS OUT absolute pressureLight source voltage
Interference fringes light level
Interference fringes contrast
4 to 20 mA output conditions
Power supply voltage

Constant
monitoring

Logging〇〇〇〇〇〇〇〇〇〇〇〇〇〇〇―〇―――* Monitors a total of 35 items including the 10 items above.

Improved maintenance
The FI-900 comprises three simple units. If faults are identified with the self-diagnostic function, only faulty units need to be replaced, which means the device can be quickly restored for use on the field.

(1)
(2)
(3)

Unit part names(1) Optical sensor unit
(2) Main controller(3) Power supply unit

Illustration of unit replacement

Device with each unit mounted insideBroad range of gases measured
Measurements are conducted using gas-specific refractive indexes capable of a broad range of gas measurement, making it
capable of measuring over 80 types of gases.
Measurement of additional gas types is also possible to suit requirements (gases in the list are an example).
In addition to air and nitrogen, the sensor can also be used with various base gases such as argon and CO2.
[0 -100% LEL]

[0-100 vol%]Measuring Gas

Measurement
Range

Base Gas

Butadiene
2,3,3,3-Tetrafluoropropene
AcetoneAcetonitrile
Acrylonitrile
BenzeneCyclohexane
Cyclopentanone
Dichloromethane
Dimethyl ether
EthaneEthyl alcohol
Ethyl acetate
Ethylcyclohexane
Ethylene
Hydrogen
Isoprene
Isopropyl alcohol
M-Xylenehexafluoride
Methyl alcohol
Methyl ethyl ketone
Methyl isobutyl ketone
Methyl methacrylate
Methylcyclohexane
Butyl acetate
Normal heptane
Normal hexane
Normal propyl alcohol
PropaneR-454C
StyreneToluenePolyvinyl chlorideXylene

0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL
0 -100% LEL

Air
Air
Air
Air
Air
Air
Air
AirAir
Air
Air
Air
Air
Air
Air
Air/N2
Air
Air
Air
Air
Air
Air
Air
Air
Air
Air
Air
Air
Air
Air
Air/N2Air
Air
Air

Measuring Gas[Others]
Measurement
Range

Ammonia0-100 vol%Carbon dioxide

0-100 vol%Deuterium
Ethylene

0-100 vol%0-100 vol%Hydrogen*1

0-100 vol%Methane
FC218
PropaneSulfur hexafluoride

0-100 vol%0-100 vol%0-100 vol%0-100 vol%*1

Base Gas

Measuring Gas

Measurement
Range

Base Gas

N2
Air/N2/
Hydrogen
Air
N2
Air/N2/CO2
Argon/
Methane
Air
Air
N2Air

Normal heptane
AcetoneBenzeneCarbon dioxide
Deuterium
Dichloromethane
Ethyl acetateHydrogen
MethaneNormal hexane
Propylene
Butadiene
Dichloromethane
Ethylcyclohexane
Methylcyclohexane
TolueneTrichloroethylene
Hydrogen

0-8 vol%
0-5 vol%
0-5 vol%
0-5 vol%
0-5 vol%
0-5 vol%
0-5 vol%
0-5 vol%
0-5 vol%
0-5 vol%
0-5 vol%
0-2 vol%
0-2 vol%
0-1 vol%
0-1 vol%
0-1 vol%
0-1 vol%
40-100 vol%N2N2Air
Air
N2Air
Air
N2Air
N2N2
N2Air
Air
Air
Air
Air
Methane[0-50 vol%]Measuring Gas

Measurement
Range

Base Gas

Butadiene
Carbon dioxide
Chlorofluorocarbon 22
Hydrogen
Propylene

0-50 vol%0-50 vol%0-50 vol%0-50 vol%0-50 vol%N2Argon
N2N2
N2*1 Specify the optional SUS sensor part.

Contact us for other gas types.

[0-20 vol%]Measuring Gas
Dichloromethane
Ethylene
Hydrogen
Propylene

Measurement
Range

Base Gas

0-20 vol%0-20 vol%0-20 vol%0-20 vol%Air
Air/N2N2
N2[0-10 vol%]Measuring Gas
Carbon dioxide
DichloromethaneHydrogenNormal hexane
Propylene

Measurement
Range

Base Gas

0-10 vol%0-10 vol%0-10 vol%0-10 vol%0-10 vol%AirAirN2
Air/N2
N2

Designed to suit various customer requirements—gas concentration measurements,
gas concentration control, purity measurements, explosion prevention!
Examples of industry applications

Hydrogen production

Painting (such as automobile painting)

Gravure printing

Use: hydrogen purity measurement

Use: VOC concentration control, explosion prevention

Use: VOC concentration control, explosion prevention

Petroleum refining

Petrochemicals (VCM plants, etc.)

Foodstuff (breweries, etc.)

Use: hydrogen concentration measurement
during hydrodesulfurization process

Use: VCM and other process gas
concentration measurement

Use: CO2 concentration measurement

Specifications
Model
Measuring principle
Measuring gas
Measuring range
Alarm setpoint
Measuring accuracy
Response time
Measuring method
Display function
External output
Communications output
Alarm relay contact 1
Alarm relay contact 2
Fault alarm contact
Power supply

FI-900
Optical interferometric method
Combustible gases, solvent vapors, inert gases
Depending on gas specifications
Depending on gas specifications
F.S. within ±3% (under same conditions, refer to separate "Specifications for measuring gas.")T90: within 30 seconds (refer to separate "Specifications for measuring gas.")Specified flow gas feed from external sampling unit
Full-dot LCD (with backlight)
4 to 20 mA DC (insulated, current throw type), permitted resistive load 300 Ω or less, minimum resolution 0.01 mA or less
RS-485 (MODBUS) communication function
Non-voltage contact, contact capacity 1 A 30 V DC (resistive load)
Non-voltage contact, contact capacity 1 A 30 V DC (resistive load)
Non-voltage contact, contact capacity 1 A 30 V DC (resistive load)
24 V DC±10% / 100 V to 240 V AC±10% 50/60Hz*The ATEX/IECEx specifications apply to DC power source only
Max. 6 W (24 V DC±10%) / Max. 20 VA (100 V to 240 V AC±10% 50/60 Hz)*The ATEX/IECEx specifications apply to DC power source only
IP66/67 or equivalent-20 to +60°C (ATEX/IECEx specifications) / -20 to +57°C (Japan Ex specifications)(no sudden changes)
95% RH or less (no condensation/use of condensible gases within unit) (no condensation)
Atmospheric pressure or equivalent (no pulses)
Approx. 286 (W)x 453 (H) x 150 (D) mm (excluding protrusions)
Approx. 23 kg
Flameproof enclosures
Ⅱ 2G Ex db ⅡB+H2 T4 Gb (ATEX)
Ex db ⅡB+H2 T4 Gb (IECEx)
Ex d ⅡB+H2 T4 (Japan Ex)
Status monitoring in 4 separate categories• FAILURE• FUNCTION CHECK• MAINTENANCE REQUIRED• OUT OF SPECIFICATION
Control key, Allen key (size 2, size 6), cable ground, plug, fuse (250 V 1A)

Power consumption
Protection classOperating temperature
range
Operating humidity range
Usage pressure range
Outer dimensions
WeightExplosion-proof structure
Explosion-proof classSelf-diagnostic
function
Accessories

Outer diagram (including sample unit, suction pump, etc.*)
600
Nameplate200

OUT（ Rc1/4 ）REF IN（ Rc1/4 ）

200
6-φ12

Illustration of piping for pump suction type（186）25

GAS IN（ Rc1/4 ）Line filter
Three-wayswitching cock

Fixed orifice Pressure gauge
Measurement

Needle valve
Pressuregauge

Sample gas

570

Three-wayswitching cock

540

600

Line filter

Zero

Needle valve
Pump

Exhaust(released toatmosphere)

Reference gas
Line filter

Pump
FI-900

Needle valve

FI-900* This detector must be used in combination with a sampling unit.
Contact us if you require a sampling unit.

RIKEN KEIKI Co., LTD
2-7-6 Azusawa, Itabashi-ku, Tokyo 174 -8744, Japan
Phone: +81-3-3966-1113
Telefax: +81-3-3558-9110
E-mail: intdept@rikenkeiki.co.jp
Website: https://www.rikenkeiki.co.jp/english* Details included in this catalog
are subject to change without
notice as performance
improvements are made.

PC3E-0430-201200