Figure 1. Model 80T150U Adjustments.

TB 9-5905-229-24

(f) Select the C position, set the Cool/Heat Source to 70 C to 90C, and again

allow the reading to stabilize.

(g) Adjust R4 (fig. 1) to obtain a multimeter reading that agrees with the

Cool/Heat Source as monitored by the thermometer C 0.05 mV dc.

(h) Set the Cool/Heat Source to 0.00 F. Select the F position and verify that

the output is within 4 mV dc of the Cool/Heat Source thermometer reading.

(i) If readjustment is necessary, repeat technique of (d) through (h) above until

readings can be obtained without adjustment.

(j) Set the 80T-150U switch to the OFF position and remove the 80T-150U

from the DVM.

(k) Reassemble the 80T-150U.

Figure 1. Model 80T150U Adjustments.

(2) Adjustments (80T-150UA)

NOTE

Output is 1 mV per degree (Celsius or Fahrenheit).

(a) Access the interior of the temperature-to-voltage converter by removing the

bottom case screw and separating the case halves.

(b) Connect the 80T-150UA to the multimeter and select 500 mV dc range.

into the Cool/Heat Source thermometer monitored 0 C and allow a full 5 minutes for the

reading to stabilize.

(d) Adjust VR3 and VR1 (fig. 2) to obtain the following reading:

0.00 0.05 mV dc.

(e) Select the F position of the switch and adjust VR2 (fig. 2) to obtain the

following reading: 32.0 0.1 mV dc.

(f) Select the C position, set the Cool/Heat Source to 70 C, and again allow

the reading to stabilize.