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L2.
Direct Reading Thermometer
Without changing the physical configuration of RT and RH, modify your breadboard
circuit to implement your design for the direct reading thermometer of prelab part P1.
Set up the DMM so you are now measuring the voltage VT in mV.
Repeat the same VSUPPLY data points as you used in part L1. Record the value of VT in
mV at each point. How well do the mV readings of temperature correspond to the
temperatures you recorded in part L1?
If there is a disagreement, think of as many reasons as you can that might explain the
discrepancy. If you have time, modify your circuit to improve the agreement, and
repeat your measurements to verify the improved performance.
CAUTION! Be sure not to confuse the roles of the heater resistor R H and the
temperature sensor resistance RT. The heater RH remains connected to the power
supply; it is only there to cause the temperature change. The temperature sensor
resistance RT becomes part of the voltage divider circuit you designed.
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