AWM92200V

AWM90000 Series Mass flow sensor for gases FEATURES · Ranges 0...±200 sccm1 or 0...±2 "H2O (0...±5 mbar) · Bidirectional sensing · Actual mass flow sensing · Low differential pressure sensing SERVICE To be used with dry gases only The AWM series is NOT designed for liquid flow and will be damaged by liquid flow through the sensor SPECIFICATIONS Maximum ratings Supply voltage2 8 to 15 V typ. 10 ±0.01 V 50 mW ELECTRICAL CONNECTION Power consumption Temperature limits Operating Storage Mechanical shock -25 to 85°C -40 to 90°C 100 g (5 drops, 6 axes) 1 2 3 4 5 6 7 8 Note: 1 sccm denotes standard cubic centimeters per minute 2 Output voltage is ratiometric to supply voltage December 2007 / 592 1/6 www.sensortechnics.com AWM90000 Series Mass flow sensor for gases FLOW SENSOR CHARACTERISTICS3 VS = 10 ±0.01 V, TA = 25°C Part no. AWM92100V AWM92200V Flow range (full scale) ±200 sccm ±2 "H2O Pressure range Max. flow change4 5.0 l/sec 5.0 l/sec Output voltage @ trim point 77 mV @ 200 sccm 38 mV @ 2 "H2O PERFORMANCE CHARACTERISTICS VS = 10 ±0.01 V, TA = 25°C Characteristics Zero offset Repeatability and hysteresis (combined) Ratiometricity error2 Temperature effects5 Offset Span -25 to 85 °C6 -25 to 25 °C 25 to 85 °C AWM92100V AWM92200V AWM92100V AWM92200V Sensor resistance (pin 1 - pin 2, pin 1 - pin 8) Sensor current Response time Common mode pressure AWM92100V AWM92200V Min. -15 Typ. 0 ±0.1 ±0.30 ±2.07 -3.0 25 8 5 Max. 15 ±0.35 Unit mV %FSO % reading mV %FSO % reading %FSO % reading ±1.08 -30 1.5 5 1.75 1.0 2.2 0.6 3.0 25 kOhm mA ms p si Notes: 2 Output voltage is ratiometric to supply voltage 3 A 5 micron filter is recommended for all devices. 4 Maximum allowable rate of flow change to prevent damage. 5 Temperature shifts in differential pressure devices are mostly due to the density change of the gas over temperature. 6 Shift is relative to 25 °C. 7 Assumes low TCR bridge resistance used (pins 2 and 8). 8 Requires recommended Rc value of 1K Ohm is used (pins 3 to 7) and typ. heater control circuit. Maximum current Rh. 2/6 December 2007 / 592 www.sensortechnics.com AWM90000 Series Mass flow sensor for gases OUTPUT FLOW VS INTERCHANGEABILITY VS = 10 ±0.01 V, TA = 25°C OUTPUT CURVES December 2007 / 592 3/6 www.sensortechnics.com AWM90000 Series Mass flow sensor for gases HEATER CONTROL CIRCUIT 6 Rb 7 1 kOhm 3 Rr 4 Ra 5 Rh SENSING BRIDGE SUPPLY CIRCUIT 10 V 24.9 kOhm 24.9 kOhm A) B) 2 8 1 Note: Circuits required for operation per specifications. Circuits are not on board the sensor. A) Customer supplied 1 kOhm resistor (affects temperature compensation and span voltage). B) Customer supplied 24.9 kOhm matched bridge resistors (affects null output voltage). Output is measured differentially from pins 8 to 2. HEATER CONTROL CIRCUIT (suggested) DIFFERENTIAL INSTRUMENTATION AMPLIFIER CIRCUIT (OPTIONAL)  2 R + R1  R4   (V2 − V1 ) + VOffset VO =  2 R  R  1   3   R6  where VOffset = VS  R +R   5 6 4/6 December 2007 / 592 www.sensortechnics.com AWM90000 Series Mass flow sensor for gases OUTLINE DRAWING 13.08 (0.515) 8x3.05 (0.12) 7x2.54 (0.10) 8x0.51 (0.02) 8x0.25 (8x0.01) 15.75 (0.62) 17.02 (0.67) 1.02 (0.04) 32.39 (1.28) 12.57 (0.50) 27.94 (1.10) 1.14 (0.05) 2x Ø 1.17 (2x Ø 0.05) 13.21 (0.52) 2.79 (0.11) Ø 3.81 (Ø 0.15) 2x Ø 4.70 (2x Ø0.19) 10.41 (0.41) 19.3 (0.76) 30.48 (1.20) mass: approx. 5.6 g dimensions in mm (inches) December 2007 / 592 5/6 www.sensortechnics.com AWM90000 Series Mass flow sensor for gases GAS CORRECTION FACTORS9 Gas type 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) Correction factor (approx.) 0.510 0.710,11 0.95 1.0 1.0 1.0 1.0 1.0 1.1 1.1 1.35 1.35 1.35 Notes: 9 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. 10 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 11 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 ±200 sccm Dry gas AWM92100V Pressure range ±2 "H2O (±5 mbar) Dry gas AWM92200V 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 December 2007 / 592 www.sensortechnics.com