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 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 E / 11723 / A 1/6 www.sensortechnics.com 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. E / 11723 / A 2/6 www.sensortechnics.com 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 E / 11723 / A 3/6 www.sensortechnics.com 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 E / 11723 / A 4/6 www.sensortechnics.com 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 P2 Ø 2.0 (Ø 0.08) 1 2 3 4 5 6 7.9 (0.31) 12.7 (0.50) mass: approx. 14 g third angle projection dimensions in mm (inches) Note: 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). E / 11723 / A 5/6 www.sensortechnics.com 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 guarantee 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. E / 11723 / A 6/6 www.sensortechnics.com