AWM2000 Series Mass flow sensor for gases FEATURES · Ranges 0...±30 to 0...±1000 sccm1 or 0...±4 "H2O (0...±10 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 ELECTRICAL CONNECTION Maximum ratings Supply voltage2 Power consumption 8 to 15 V typ. 10 ±0.01 V max. 50 mW typ. 30 mW Temperature limits Operating Storage -25 to 85°C -40 to 90°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 June 2005 / 581 1/6 www.sensortechnics.com AWM2000 Series Mass flow sensor for gases FLOW SENSOR CHARACTERISTICS3 VS = 10 ±0.01 V, TA = 25°C Part no. Flow range (full scale) Pressure range AWM2100V ±200 sccm 5.0 l/sec AWM2150V ±30 sccm 5.0 l/sec 11.8 mV @ 25 sccm 5.0 l/sec 20 mV @ 2 "H2O 5.0 l/sec 50 mV @ 650 sccm ±4 "H2O AWM2200V AWM2300V Output voltage @ trim point Max. flow change4 ±1000 sccm 30 mV @ 100 sccm PERFORMANCE CHARACTERISTICS VS = 10 ±0.01 V, TA = 25°C Characteristics Zero offset Min. Typ. Max. Unit -1.0 0 1.0 mV Repeatability and hysteresis AWM2300V ±1.0 (combined) all others ±0.35 Temperature effects5 Offset -25 to 85 °C6 Span -25 to 25 °C 25 to 85 °C Sensor resistance (Pin 2 - Pin 1, Pin 6 - Pin 1) Sensor current (Pin 2 - Pin 1, Pin 6 - Pin 1) Response time Common mode pressure % reading ±0.20 mV AWM2100V 2.5 AWM2150V 5.0 AWM2200V 22.05 AWM2300V 5.0 AWM2100V -2.5 AWM2150V -5.0 AWM2200V -22.05 AWM2300V -5.0 % reading 5 1.0 kOhm 0.6 mA 3.0 ms 25 p si Notes: 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. 2/6 June 2005 / 581 www.sensortechnics.com AWM2000 Series Mass flow sensor for gases OUTPUT FLOW VS INTERCHANGEABILITY VS = 10 ±0.01 V, TA = 25°C 8 7 8 OUTPUT CURVES June 2005 / 581 3/6 www.sensortechnics.com AWM2000 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 R1 R3 R6 where VOffset = VS + R R 6 5 4/6 June 2005 / 581 www.sensortechnics.com AWM2000 Series Mass flow sensor for gases OUTLINE DRAWING 6.3 (0.25) 2.8 (0.11) 7.60 (0.30) 1.40 (0.055) 2.9 (0.114) 1.8 (0.07) 5.1 (0.20) 54.4 (2.14) 8.4 (0.33) P1 P2 31.5 (1.24) 23.6 (0.93) 2.8 (0.11) 1.0 (0.04) 1 2 3 4 5 6 0.6 (0.025) 1.52 (0.06) mass: approx. 10.8 g 2.5 (0.10) 23.9 (0.94) 30.5 (1.20) 5.1 (0.20) 4.1 (0.16) 7.3 (0.287) 12.7 (0.50) 15.5 (0.61) 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). June 2005 / 581 5/6 www.sensortechnics.com AWM2000 Series Mass flow sensor for gases GAS CORRECTION FACTORS9 Gas type 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 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: 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 Dry gas Hydrogen gas11 ±30 sccm AWM2150V --- ±200 sccm AWM2100V AWM2100VH ±1000 sccm AWM2300V AWM2300VH Pressure range Dry gas ±4 "H2O (±10 mbar) AWM2200V 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 June 2005 / 581 www.sensortechnics.com