Interactive Catalog Replaces Catalog Pages Honeywell Sensing and Control has replaced the PDF product catalog with the new Interactive Catalog. The Interactive Catalog is a power search tool that makes it easier to find product information. It includes more installation, application, and technical Click this icon to try the new information than ever before. Interactive Catalog. Sensing and Control Honeywell Inc. 11 West Spring Street Freeport, Illinois 61032 Airflow Sensors AWM 2000 Series Microbridge Mass Airflow/Unamplified Figure 1 Heater Control Circuit FEATURES 1 Bidirectional sensing capability 1 Actual mass air flow sensing 1 Low differential pressure sensing Figure 2 Sensing Bridge Supply Circuit The AWM2000 Series microbridge mass airflow sensor is a passive device com- prised of two Wheatstone bridges. The heater control circuit in Figure 1 is re- quired for operation per specifications. The sensing bridge supply circuit in Fig- ure 2 is also required for operation per specifications. These two circuits are not on board the package and must be sup- plied in the application. The differential Figure 3 amplifier in Figure 3 is a useful interface Differential Instrumentation Amplifier Circuit for the sensing bridge. It can be used to introduce the gain and to introduce volt- age offsets to the sensor output as refer- enced in Equation 1. Note: For applications sensing hydrogen or helium, 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 () 68 Honeywell 1 MICRO SWITCH Sensing and Control 1 1-800-537-6945 USA1F1-815-235-6847 International 1 1-800-737-3360 Canada