50S & 50D Thermometer
Calibration Information
10
position until the display is locked in self-test (all LCD segments on). This thermometer is now in the
Reference Junction Sensor calibration mode. Shorting out the VIEW switch grid turns off a filter so that
the reading stabilizes immediately.
13.
Using the 80T-150U and the Fluke 87 Series IV Digital Multimeter (DMM), measure the reference
junction transistor temperature by placing the 80T-150U probe tip against Q1, located in the middle hole
of the isothermal block. Wait for the temperature reading to stabilize.
14.
Adjust R16 for a temperature reading that is the same as displayed on the DMM.
15.
Turn the thermometer OFF by shorting the ON/OFF switch grid, and reattach the top-case.
5520A
50S or 50D
Thermometer +
_
Copper
wire
zf07f.eps
Figure 5. Calibration Connections
