FMO Series - First Sensor

FMO Series
Mass flow sensors for gases
FEATURES
· Ranges 0...±25 and 0...±1000 sccm1
· Bidirectional sensing
· Actual mass flow sensing
· Ceramic flow tube
· Manifold mount/O-ring sealed
· Sensortechnics PRO services
· RoHS compliant
MEDIA COMPATIBILITY
To be used with dry gases only.
The FMOM025HB is a special sensor for
hydrogen (H2) flow.
The FMO series is NOT designed for liquid
flow and will be damaged by liquid flow through
the sensor.
SPECIFICATIONS
ELECTRICAL CONNECTION
Maximum ratings
Supply voltage2
8 to 15 V
typ. 10 ±0.01 V
Power consumption
max. 60 mW
Temperature limits
Operating
Storage
-40 to 125°C
-40 to 125°C
Mechanical shock
100 g (5 drops, 6 axes)
P1
P2
1 2 3 4 5 6
Note:
1
sccm denotes standard cubic centimeters per minute
2
Output voltage is ratiometric to supply voltage
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FMO Series
Mass flow sensors for gases
FLOW SENSOR CHARACTERISTICS3
(VS = 10 ±0.01 V, TA = 25°C)
Part no.
Flow range
(full scale)
Max. flow
ch an g e4
Output voltage
@ trim point
FMOM025HB
±25 sccm
5.0 l/sec
8.5 ±1.5 mV @ 25 sccm
FMOL001DB
±1000 sccm
5.0 l/sec
54.7 ±3.7 mV @ 1000 sccm
PERFORMANCE CHARACTERISTICS
(VS = 10 ±0.01 V, TA = 25°C)
Characteristics
Zero offset
Min.
Typ.
Max.
FMOM025HB
-1.0
0
1.0
FMOL001DB
-1.5
0
1.5
Unit
mV
Repeatability and hysteresis
FMOM025HB
±0.35
(combined)
FMOL001DB
±0.50
% reading
Temperature effects5
Offset
-25 to 85 °C
±0.20
Span
-25 to 25 °C
2.5
25 to 85 °C
-2.5
mV
% reading
Response time
Common mode pressure
1.0
3.0
ms
150
p si
Notes:
3
A 5 micron filter is recommended for all devices.
4
Maximum allowable rate of flow change to prevent damage.
5
Shift is relative to 25 °C.
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FMO Series
Mass flow sensors for gases
FLOW SPECIFICATIONS
(VS = 10 ±0.01 V, TA = 25°C)
FMOM025HB
FMOL001DB
Press.
(µbar)
Flow
(sccm)6
Nom.
(mV)
Tol.
(± mV)
Press.
(mbar)
Flow
(sccm)6
Nom.
(mV)
Tol.
(± mV)
20
30
9.9
1.5
2.23
1000
54.7
2.0
17
25
8.5
1.5
1.52
800
53.0
2.0
14
20
6.8
1.5
0.94
600
49.3
2.5
10
15
5.2
1.0
0.49
400
42.5
3.5
7
10
3.5
1.0
0.19
200
29.8
4.0
3
5
1.7
1.0
0.00
0
0.0
1.5
0
0
0.0
1.0
-0.19
-200
-29.8
4.0
-0.49
-400
-42.5
5.0
-0.94
-600
-49.3
6.0
-1.52
-800
-53.0
6.0
-2.23
-1000
-55.2
6.0
Note:
6
Devices are calibrated in mass flow. Tolerance values apply to calibration type only.
OUTPUT VS. FLOW CURVES
FMOM025HB
FMOL001DB
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FMO Series
Mass flow sensors for gases
HEATER CONTROL CIRCUIT
SENSING BRIDGE SUPPLY CIRCUIT
Note:
These circuits are required for operation per specifications. Circuits are not on board the sensor.
DIFFERENTIAL INSTRUMENTATION AMPLIFIER CIRCUIT (optional)
 2 R + R1  R4 
 (V2 − V1 ) + VOffset
VO =  2
 R1  R3 
 R6 

where VOffset = VS 
 R6 + R5 
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FMO Series
Mass flow sensors for gases
OUTLINE DRAWING
30.5
(1.20)
27.7
(1.09)
14.0
(0.55)
32.2
(1.19)
7.62
(0.30)
6 5 4 3 2 1
2.5
(0.10)
0.64
(0.025)
34.0
(1.34)
17.3
(0.68)
3.0
(0.12)
4.8
(0.19)
10.9 8.4
(0.43) (0.33)
Ø 6.2
(Ø 0.24)
Ø 3.0
(Ø 0.12)
Ø 3.51
(Ø 0.138)
2.54
(0.10)
P1
Ø 2.0
(Ø 0.08)
P2
1 2 3 4 5 6
7.9
(0.31)
12.7
(0.50)
third angle projection
mass: approx. 14 g
dimensions in mm (inches)
Note 1: Positiv flow direction is defined as proceeding from port 1 (P1) to port 2 (P2) and results
in positive output (pin 6 > pin 2). Negative flow direction is defined conversely and results
in negative output (pin 6 < pin 2).
Note 2: Viton O-rings for manifold mounting are included in delivery.
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FMO Series
Mass flow sensors for gases
GAS CORRECTION FACTORS7
Gas type
Correction factor (approx.)
0.58
0.78,9
0.95
1.0
1.0
1.0
1.0
1.0
1.1
1.1
1.35
1.35
1.35
Helium (He)
Hydrogen (H2)
Argon (Ar)
Nitrogen (N2)
Oxygen (O2)
Ai r
Nitric oxide (NO)
Carbon monoxide (CO)
Methane (CH4)
Ammonia (NH3)
Nitrous oxide (N2O)
Nitrogen dioxide (NO2)
Carbon dioxide (CO2)
Notes:
7
Gas correction factors are referenced to nitrogen (N2) as calibration gas type. Approximate gas correction factors are provided
as guidelines only. Individual gas types may perform differently at temperature extremes and varying flow rates.
8
When sensing Hydrogen (H2) or Helium (He) it may be necessary to power the mass flow sensor using increased supply voltage:
Hydrogen typ. 12 V, Helium typ. 15 V
9
Hydrogen (H2) flow measurement requires the use of a special sensor. These devices provide normal operation when sensing
hydrogen flow and are designated with an "H" at the end of the order number.
ORDERING INFORMATION - AVAILABLE LISTINGS
Flow range
Dry gas
Hydrogen gas9
±25 sccm
-
FMOM025HB
±1000 sccm
FMOL001DB
-
Sensortechnics PRO services:
· Extended warranty period of 2 years
· Improved performance characteristics
· Custom product modifications and adaptations even for small quantities
· Advanced logistics models for supply inventory and short delivery times
· Technical support through application engineers on the phone or at your site
· Fastest possible technical response for design and QA engineers
... plus other services on request
Sensortechnics reserves the right to make changes to any products herein. Sensortechnics does not assume any liability arising out of the
application or use of any product or circuit described herein, neither does it convey any license under its patent rights nor the rights of others.
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