Minute flow rate measuring and transmitting withflameproof

MA-920 Series
INTELLIGENT, PURE ELECTRONICS
MICRO FLOWMETER■ OUTLINE
MA-920 MICRO FLOWMETER is a metal tube variable area
flowmeter which has local indication with transmitting of minute flow rate of liquids and gases.
TOKYO KEISO's long time production know-how and recent
electronics technology have been successfully combined.
The existing micro flowmeters generally need a signal linearizer due to mechanical problem of very minute sensing part.
In MA-920, integrated microprocessor takes care of these
automatic compensation based on individual stored calibration data and achieves high accuracy even for small flow rate.
The 4 to 20 mA with 2-wire system makes field wiring easier.

■ FEATURES● Covers very low flow rates of 0.6 to 3 L/h● 2-wire 4 to 20 mA DC output● Magnetic field sensor detects the float movement withelectronics to eliminate hysteresis.
High accuracy and repeatability have been achieved.
● Easy- to- read digital LED display● No liquid dampers are needed even for gas measurement applications● Ex d IIC T6 flameproof construction suitable even for
Hydrogen atmosphere■ MODEL CODE
Model code
MA-92–Flowdirection

1235Material– 1– 9

■ MAIN APPLICATIONS
Small flow measurement, transmitting and control for● Liquid chemical injection and feed
● Gas injection and feed
● Various services for test plant and pilot plant● Assembling onto various devices and equipment

Description–Process
Connection

Valve

1
234
589A
BX
Y
Z–––00VU
VL

Bottom to Top
Bottom to Top side
Bottom side to Top side
Bottom rear to Top rearStandard material
Special material
Rc1/4
Rc3/8
Rc1/2Rc3/4
Rc1
10AJIS10KFF
15AJIS10KFF
20AJIS10KFF
25AJIS10KFF
Other thread connection
Other flange connection
Other special connection
Not provided
Needle valve at outlet (Upper)
Needle valve at inlet (Lower)

TG-F283-9E
10th edition Oct 2019 K
1st edition May 1996

MA-920 Series MICRO FLOWMETER■ STANDARD SPECIFICATIONMEASURING FLUID

Liquids and Gases
Viscosity limit for liquid flow measurement
Meter size

Viscosity (Max.)½¾, 1

2.0 mPa·s
5.0 mPa·s(Free from solids and particles)
MEASURING RANGE
Liquid (Water)Min.
0.6 to 3L/hMax.
60 to 600
L/h
Measuring range is subject to liquidviscosity.

Gas (Air, 0°C, 1atm)
RANGE ABILITY(Accuracy guranteed range)

FLUID TEMPMin.
10 to 100
L/h (nor)Max.
2.2 to 22
m3/h (nor)
10:1
Rangeability of the meter with the fullscale range smaller than 5L/min (water)
is 10:2. It may differ depending on theliquid viscosity.
0 to 120°C (See the explosionproof
specifications for details.)

FLUID PRESS.
Standard type: Max. 2.94 MPa
High pressure type : Max.19.6 MPa
Allowable pressure is subject to the flange rating when theconnection is flange type.
Material of high pressure type is SUS 316.
PROCESS CONNECTION
Std.
Screw (1/4, 3/8, 1/2, 3/4 or 1")
JIS10KFF flange (10A, 15A, 20A, or25A)Opt.
NPT or other screw
Other flanges than JIS10KFF
FLOW DIRECTION
Bottom to Top, Bottom to Top side,
Bottom side to Top side, or Bottom
rear to Top rear
INSTALLATION

INDICATION
Upper (main display): Four digits for measurements and error codes
Lower (sub display): Five digits for supplementary information
ACCURACY (Indication and output)
10 L/h or more of F.S. (water)±2%F.S.
Less than 10 L/h of F.S. (water)±3%F.S.
100 L/h (nor) or more of F.S. (air)±2%F.S.
REPEATABILITY
0.5%F.S.
OUTPUT SIGNAL 4 to 20 mA DC (2-wire system)
Allowable load resistance: 600Ω or less (at 24 V DC, including wiringresistance)(500Ω or less for ATEX-certified)
RESPONSE TIME Within 0.4sec.
POWER SOURCE 24 V DC ±10% (Operating voltage range:
12 to 33 V DC)
TEMP.EFFECT
Within 0.02% (F.S.) /°C
ENCLOSURE
Flameproof
Ex d IIC T6(TIIS-certified)Ex d IIC T6 Gb(NEPSI-certified)Ex d IIC T6(KOSHA-certified)
CABLE ENTRY
TIIS-certified : G1/2
(Flameproof cable gland provided)
Cable diameter : ø8–12 mm
NEPSI-certified : G1/2
KOSHA-certified : G1/2
CABLE TERMINATION M4 screw
AMBIENT TEMP.
−20 to 55°C (TIIS-certified, NEPSI-certified,KOSHA-certified)
ALLOWABLE FLUID TEMP.
ClassTIIS-certified
NEPSI-certified
KOSHA-certified

MATERIAL
MASS (APPROX.)

Under the ignition temp.

To be referred to MATERIALCONSTRUCTION below.
3 kg (Rc1/4 connection type)■ MATERIAL CONSTRUCTION

Supported by process piping
1234■ OPERATING PRINCIPLE
As shown in figure below a magnet with vertical polarity is molded in
the float. Float moves vertically in response to the flow rate of fluid.
An oval shaped magnetic field exists between N pole and S poleof the magnet.Two magnetic field sensors whose sensitivities
are designed equal are located at 90° angle, close to the taperedtube. These 2 sensors generate output signal which corresponds
to the strength of magnetic field and its angle. By differential dataprocessing of these outputs from 2 sensors, the angle of magnetic
field which represents the position of float is obtained. Thus, the flowrate of fluid can be calculated from the position of float.
Flameproof housing

Float

Tapered tube

Tapered tube
③T6

NSElectric circuit

M

56No.
123456Part Name
Body
Tapered tube
Float
Packing
Indicator / Transmitter
Fittings

Material
SCS14SUS316
SUS316 ✽1PTFE ✽2
ADC12SUS304 (std.) or SUS316 ✽3✽1: PPS resin / Titanium will be used for 1/2" meter size, and PPS

Magnetic field sensor②①NS
Position offloat

NS

Shape ofmagnetic
fieldresin / SUS316 will be used for 3/4 and 1" meter sizes in gas
measurement applications.
✽2: Packing is not an external pressure part.
✽3: Materials of flange and connection fitting can be selected.
Specify them when ordering.

③②①2

TOKYO KEISO CO., LTD.

TG-F283-9E

MA-920 Series MICRO FLOWMETER■ DIMENSIONS● Flow direction:BOTTOM SIDE (or REAR) TO TOP SIDE

● Flow direction: BOTTOM TO TOP, Screw connection(or REAR), Screw (Flange) connection
1602-Rc

A

2-DL

118

M118

L

M

(120)
(180)

(Max.150)(Max.75)

(120)
(180)

(Max.150)(Max.75)(mm)
Metersize

Full scale
Water
L/hAirL/h (nor)

Connection screw size (D)

¼⅜

✽

✽

½
¾

29.9
300

4900

180

1600

22000

200✽

630

180

✽

½180160

✽

✽

¾230

✽

(mm)
Full scale
Meter
Air
size Water
L/h L/h (nor)1230

Connection screw size (D)

✽✽

180

180

160

230

180✽

180✽

180✽

160

¼
L

½⅜
A

LA

L

¾A

L

1AL

A

½¾

29.9

630

225 19 235 23 220 27 300 32 310 38

3004900

225 19 235 23 240 27 230 32 310 38

160022000

245 19 235 23 240 27 250 32 240 38✽: Thread adaptor provided

A dimension for flange connection is 160mm● Flow direction: BOTTOM TO TOP, Flange connection● Flow direction:BOTTOM TO TOP, Screw connection,
Needle valve provided at outlet
2-RcD

L

L

118

M

118

M

(120)
(180)

(Max.150)(Max.75)(120)(Max.150)(180)(Max.75)

L (mm)
Metersize

Full scale
Water
L/hAirL/h (nor)½¾29.9630

300

4900

1600

22000

L (mm)

260

Metersize

Full scale

Connection screw size (D)

Water
L/hAirL/h (nor)

¼⅜

½

¾

1

½
¾

29.9

630

245

225

250

295

295

300

4900

245

225

250

260

295

1

600

22000

265
280
290

225
260
270

250
240
270

260
275
250

260
275
285

✽1
✽2
✽3

✽1: Up to Air 8300 L/h (nor)✽2: Up to Water 400 L/h, Air 11000 L/h (nor)✽3: Up to Water 600 L/h, Air 22000 L/h (nor)L (mm) may vary depending on the difference in upstream and downstream pressure ofthe valve.
A valve is attached as standard. Its maximum allowable working pressure is 3 MPa.

TG-F283-9E

TOKYO KEISO CO., LTD.

3

MA-920 Series MICRO FLOWMETER■ WIRING■ ORDERING FORM
Specify the following for order / inquiry ;MA-920 terminal

MA-92 ■ - ■ ■ - ■ ■FLUID NAME__________________DENSITY__________________VISCOSITY_____ ■

mPa•s ■ _____PRESS.

_____ ■

MPa ■ _____

TEMP.

_____ ■°C ■ _____MEASURING RANGE_____ ■ L/hCONNECTION SIZE_____ ■ mm ■ _____CKCKMODEL CODE– Ａ +ReceiverＥ■ OPTIONS

100● Magnet Strainer(75)The strainer installed at upstream eliminates particles inOUTthe fluid.
Select a proper mesh of thefilter adequate for the size ofparticles.
A magnet is molded in theSNN
float and in case ferrous
Spowder are involved in thefluid, smooth movement offloat will not be obtained.
IN
It is recommended to installa Magnet Strainer in upstream of the line to eliminate the ferrous contents.

■ L/h (nor) ■ _____

CONNECTION STANDARD■ Rc■ JIS10KFF ■ _____MATERIAL■ Standard■ Special (Specify)

SPECIAL INSTRUCTION IF ANY;____________________________________________________________________________________________________________________

Operating pressure (Max.): 1.5 MPa (Standard)
Operating temperature (Max.) : 200°C
Nominal size
: Rc1/4", 3/8", 1/2"
Filter: 100 mesh/inch(Option : Up to 200 mesh/inch)
Material: Body: SCS14
Filter: SUS304, SUS316* Specification is subject to change without notice.

Head Office : Shiba Toho Building, 1 – 7 – 24 Shibakoen, Minato-ku, Tokyo 105 – 8558
Tel : +81-3 – 3431 – 1625 (KEY) ; Fax : +81-3 – 3433 – 4922
e-mail : overseas.sales@tokyokeiso.co.jp ; URL : https://www.tokyokeiso.co.jp
4TG-F283-9E