Airflow Airflow Sensors AWM1000 Series Microbridge Mass Airflow/Unamplified Figure 1 Heater Control Circuit FEATURES 1 Cost-effective microbridge technology 1 Accurate, repeatable airflow sensing 1 Bi-directional sensing capability 1 Low differential pressure sensing Figure 2 Take advantage of microbridge mass Sensing Bridge Supply Circuit flow sensor technology. The AWM1000 series mass flow sensor provides all of the outstanding performance benefits of the standard AWM2000 series in a more cost- effective sensor platform. This device pro- vides accurate, repeatable flow sensing. Sensor to sensor interchangeability specifications are approximately twice as large as compared to the AWM2000 se- ries. Figure 3 Differential Instrumentation Amplifier Circuit The heater control circuit in Figure 1 and the sensing bridge supply circuit in Figure 2 are both required for operation per specification. These two circuits are NOT on board the sensor and must be sup- plied in the application. The differential amplifier circuitry in Figure 3 may be use- ful in providing output gain and/or intro- ducing voltage offsets to the sensor out- put (Ref. Equation 1). NOTE: For applications involving sens- ing hydrogen (H ) gas or helium (He) gas, 2 see Application Note 3, page 131. Equation 1: 2R +R R 2 1 4 V J V -V +V offset o 2 1 R R ()1 ( 3)( ) R 6 where V offsetJV S R R 6+ 5 () Honeywell1 Sensing and Control 1 1-800-537-6945 USA1 F1-815-235-6847 International 1 1-800-737-3360 Canada 65Airflow Sensors AWM1000 Series Microbridge Mass Airflow/Unamplified AWM1000 SERIES ORDER GUIDE (Performance Characteristics 10.0 0.01 VDC, 25C) Catalog Listings AWM1100V AWM1200V AWM1300V Flow Range (Full Scale) 200 sccm +1000 sccm to -600 sccm Pressure Range (See Application Note 1) 4.0N H O (10 mBar) 2 Output Voltage Trim Point 30 mV 100 sccm 20 mV 2.0N H O 50 mV 650 sccm 2 Null Voltage Shift, Typ. +25 to -25C, +25 to 85C 0.7 mV (max.) 0.7 mV (max.) 0.7 mV (max.) Output Voltage Shift, Max. +25 to -25C 4% Full Scale +22% Reading (Note 2) 4% Full Scale +25 to +85C 4% Full Scale -22% Reading 4% Full Scale Repeatability & Hysteresis, Max. 1% Full Scale 1% Full Scale 1% Full Scale Min. Typ. Max. Excitation (VDC) (Note 1) 8.0 100.01 15 Power Consumption (mW) 30 50 Null Voltage (mV) -1.0 0.0 +1.0 Response Time (msec) 1.0 3.0 Common Mode Pressure (psi) 25 Sensor Resistance (kW) Pin 2-Pin 1, Pin 6-Pin 1 5 Sensor Current (mA) Pin 2-Pin 1, Pin 6-Pin 1 0.3 0.6 Temperature Range Operating: -25 to +85C (-13 to +185F) Storage: -40 to +90C (-40 to +194F) Termination 2,54 mm (.100N) centers, 0,635 mm (0.025N) square Weight (grams) 10.8 Shock Rating 100 g peak (5 drops, 6 axes) Notes: 1. Output Voltage is ratiometric to supply voltage. 2. Temperature shifts when sensing differential pressure correlates to the density change of the gas over temperature. See Application Note 1. 3. Maximum allowable rate of flow change to prevent damage: 5 SLPM/1.0 sec. MOUNTING DIMENSIONS (for reference only) 66 Honeywell1 Sensing and Control 1 1-800-537-6945 USA1 F1-815-235-6847 International 1 1-800-737-3360 Canada