Resistance Check

TB 9-4920-364-35

Table 4. Potentiometer Range

Calibrator

Test instrument °C dial indication

output (mV)1

Min

Initial

Max

24.902

599

600

601

20.640

499

500

501

16.395

399

400

401

12.207

299

300

301

8.137

199

200

201

4.095

100

101

Subtract millivolt value recorded in 8 a (6) above.

b. Adjustments

(1) Set SW-6 switch to MECH. ZERO.

(2) Connect equipment as shown in figure 1.

(3) Adjust °C control for a 0 degree indication.

(4) Repeat a (6) above.

(5) Set SW-6 switch to RANGE.

(6) Adjust TRIMPOT B (fig. 2) until GALVO-1 indicates 0.

(7) Repeat (1) above.

(8) Set calibrator to standby and reverse connections at calibrator input.

(9) Adjust °C control to 1000 dial indication.

(10) Adjust output of calibrator to 41.269 mV, less millivolt value used in a (6) above.

(11) Repeat (5) above.

(12) Adjust TRIMPOT A (fig. 2) until GALVO-1 indicates 0.

(13) Repeat (1) through (12) above until no further adjustments are required.

9. Resistance Check

a. Performance Check

(1) Connect TI INPUT RES. INSUL. P-2 to HIGH and LOW terminals of

resistance standard using resistance check adapter (BH-485 and BH823, p/o TI).

(2) Set SELECTOR SWITCH SW-1 to RES.

(3) Set SW-6 switch to MECH. ZERO.

(4) Adjust GALVO-1 MECH. ZERO for a 0 indication on GALVO-1.

(5) Adjust resistance standard for 4.21 ohms.

(6) Set RESISTANCE CHECK SW-3 switch to 4.21 ohms.

(7) Set SW-6 switch to RANGE. If GALVO-1 does not indicate 0 ±5 divisions,

perform b below.

(8) Set SW-6 switch to MECH. ZERO.