Active
On
Label
TEMP
Meas Type
Analog
Analog Type
0-5V A (or B)
Warmup
0 sec
Averaging Time
00:00:00
Sampling Interval
0.0 sec
Slope
1 for Celsius
1.8 for Fahrenheit
Offset
0 for Celsius
+32 for Fahrenheit
Use Equation
On
Equation (note this is
entered all on one line
in the setup)
STEINHART(10000*X/(VREF-X)
,0.00146732513897221
,0.00023841146463031
,0.00000010078969927)
Notice measurement interval and averaging are not addressed in this setup, which will
depend on the application requirements.
Pressure Transducer (Analog Bridge Sensor)
Pressure transducers using a strain gauge (analog 4 wire bridge) is a common choice for
water level applications. These transducers are designed to be driven by an excitation
voltage, VREF for this example, and the output of the bridge is a differential reading that
will have a full scale output that is a percentage of the excitation voltage, VREF. The
sensor will have a rated pressure, and a typical full scale output for a particular excitation
voltage. This example will be for a 10 PSI transducer that has an output of 100 mV with
an excitation of 10 Volts. Since VREF is 2.5 volts (1/4 of the data sheet excitation of
10V), the Full Scale, or FS output of the sensor will be 25 mV (1/4 of the data sheet
output of 100mV). Since the Differential Input Range is 39.0625 mV, then the 25mV FS
of the sensor is always within range.
The nature of the bridge sensor will automatically place the differential reading in the
allowable common mode range of the Differential input and in this case, in the ballpark
of 1.25 volts.
32
