AWM42000 Series Mass flow sensor for gases FEATURES · Ranges 0...±25 and 0...±1000 sccm1 · Bidirectional sensing · Actual mass flow sensing · Ceramic flow tube · Manifold mount/o-ring sealed SERVICE To be used with dry gases only. The AWM42150VH is a special sensor for hydrogen (H2) flow. The AWM 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 November 2004 / 624 1/6 www.sensortechnics.com AWM42000 Series Mass flow sensor 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 AWM42150VH ± 2 5 sccm 5.0 l/sec 8.5 ±1.5 mV @ 25 sccm AWM42300V ± 1 0 0 0 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. AWM42150VH -1.0 0 1.0 AWM42300V -1.5 0 1.5 Repeatability and hysteresis AWM42150VH ±0.35 (combined) AWM42300V ±0.50 Temperature effects5 Offset -25 to 85 °C ±0.20 Span -25 to 25 °C 2.5 25 to 85 °C -2.5 Response time Common mode pressure 1.0 Unit mV % reading mV % reading 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. 2/6 November 2004 / 624 www.sensortechnics.com AWM42000 Series Mass flow sensor for gases OUTPUT FLOW VS INTERCHANGEABILITY VS = 10 ±0.01 V, TA = 25°C OUTPUT CURVES November 2004 / 624 3/6 www.sensortechnics.com AWM42000 Series Mass flow sensor for gases HEATER CONTROL CIRCUIT SENSING BRIDGE SUPPLY CIRCUIT Note: Circuits 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 R 1 R3 R6 where VOffset = VS + R R 5 6 4/6 November 2004 / 624 www.sensortechnics.com AWM42000 Series Mass flow sensor 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) 3.0 (0.12) Ø 3.0 (Ø 0.12) 2.54 (0.10) 17.3 (0.68) 4.8 (0.19) 10.9 8.4 (0.43) (0.33) Ø 6.2 (Ø 0.24) Ø 3.51 (Ø 0.138) 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 November 2004 / 624 dimensions in mm (inches) 5/6 www.sensortechnics.com AWM42000 Series Mass flow sensor for gases GAS CORRECTION FACTORS6 Gas type Correction factor (approx.) 0.57 0.77,8 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: 6 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. 7 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 8 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 Flow range Dry gas Hydrogen gas8 ± 2 5 sccm --- AWM42150VH ± 1 0 0 0 sccm AWM42300V --- 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. 6/6 November 2004 / 624 www.sensortechnics.com