Doric Instruments 475 Series Portable Digital Calibrators Calibration Manual User Manual

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gg. Adjust R53 for a display reading of 390.0 ohms.
hh. Repeat steps 3.1.2.z through 3.1.2.gg until no further adjustments are required for

correct display readings.

3.1.2 mA Input Calibration
a. Observing proper polarity, connect precision mA source to mA input jacks of

instrument.

b. Set instrument to calibrate/mA input mode.
c. Adjust mA source output to 32.00 mA.
d. The display should read 32.00 mA. If not, adjust R10 for correct reading.
e. Adjust mA source output to 3.2 mA.
f. The display should read 3.20 mA. A correction of 0.01 may be made by adjusting

R10.

g. IF R10 WAS ADJUSTED FOR THE mA READINGS, RECHECK THE OHMS

RANGE (3.1.2.z through 3.1.2.hh).

h. Carefully reassemble instrument.

CALIBRATION COMPLETED