Figure 3. Temperature circuit board.

Calibration Procedure For Exhaust Gas Temperature Tester, Model Bh112Jb Page Navigation
6

TB 9-4920-454-24

b. Adjustments

(1) Connect frequency counter between TP3 (+) and TP2 (-) (fig. 3). Frequency

counter will indicate between 97.0 and 103.0 s; if not, adjust R26 (fig. 3) for a 100 s

indication on frequency counter (R).

R66

R65

TP1

R59

R26

TP2

TP3

R69

R57

Figure 3. Temperature circuit board.

(2) Connect multimeter between TP1 (+) and TP2 (-) (fig. 3). If multimeter does not

indicate between 7.255 and 7.295 mV dc, adjust R65 (fig. 3) for an indication of 7.275 mV dc.

(3) Adjust calibrator for a dc millivolt output equal to ambient temperature

obtained in table 3, plus .017 mV.

(4) If TEMP oC indicator does not indicate 0, adjust R57 (fig. 3) for an indication of 0 (R).

(5) Adjust calibrator for a 55.820 mV dc, less millivolt equivalent to ambient

temperature, output.

(6) Adjust R59 (fig. 3) for TEMP oC indicator reading of 1397 (R).

(7) Repeat a (1) and a (3) through (8) above, as necessary, to ensure TEMP oC

indicator is in tolerance at both points.

NOTE

Perform paragraph 9 below only if adjustments were made in

8 b above.

9. Calibrator Board

a. Performance Check

(1) Place thermometer adjacent to calibrator OUTPUT terminals. Wait 10 minutes

for thermometer to stabilize and record ambient temperature.