Datasheet

Airflow Sensors AWM 2000 Series
Microbridge Mass Airflow/Unamplified
68 Honeywell1 Sensing and Control11-800-537-6945 USA1F1-815-235-6847 International11-800-737-3360 Canada
FEATURES
1 Bidirectional sensing capability
1 Actual mass air flow sensing
1 Low differential pressure sensing
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
amplifier in Figure 3 is a useful interface
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.
Figure 1
Heater Control Circuit
Figure 2
Sensing Bridge Supply Circuit
Figure 3
Differential Instrumentation Amplifier Circuit
Equation 1:
V
o
J
2R
2
+R
1
R
4
V
2
-V
1
+V offset
()()()
R
1
R
3
where V offsetJV
S
()
R
6
R
6+
R
5