TB 9-4931-217-40
(2) Connect fixed resistor directly across TI GENERATOR AC OUTPUT terminals
1 and 2.
(3) Connect TI GENERATOR AC OUTPUT terminal 2 to TI DETECTOR AC
INPUT terminal 2.
(4) Press ON/OFF pushbutton to ON. Adjust R14 (fig. 6) until meter indicates null
(low point, not zero).
(5) Set GENERATOR polarity switch alternately between + (positive) and -
(negative). If TI meter indication is not within one minor division in either position,
perform b below.
b. Adjustments (fig. 6). Set GENERATOR polarity switch alternately between +
(positive) and - (negative) while adjusting R14 for same TI meter indication in either
position.
34. Ac Detector Sensitivity
a. Performance Check
(1) Connect function/arbitrary generator 50-ohm output terminal
to
TI
DETECTOR AC INPUT terminals 1 and 2, using cable and termination.
(2) Adjust function/arbitrary generator controls for a 100 V output with frequency
at 1 kHz.
(3) Set DETECTOR SENSITIVITY HIGH/LOW switch to HIGH and rotate
DETECTOR SENSITIVITY control fully cw. If TI meter does not indicate full scale,
perform b below.
(4) Set DETECTOR SENSITIVITY HIGH/LOW switch to LOW.
(5) Adjust function/arbitrary generator controls for a 10 mV output. TI meter will
indicate full scale or near full scale.
b. Adjustments. Adjust R15 GAIN (fig. 6) for a full-scale indication on TI meter.
35. Final Procedure
a. Deenergize and disconnect all equipment.
b. Annotate and affix DA label/form in accordance with TB 750-25.
CALIBRATION PROCESS FOR KELVIN RESISTANCE BRIDGE, MODEL SP2979
36. Preliminary Instructions
a. The instructions outlined in paragraphs 36 and 37 are preparatory to the calibration
process. Personnel should become familiar with the entire bulletin before beginning
the calibration.