TB 9-6625-1314-24
CALIBRATION PROCESS FOR DIGITAL VOLTMETER, HEWLETT-PACKARD
MODEL 3440A WITH PLUG IN MODELS 3444A OR 3445A
6. Preliminary Instructions
a. The instructions outlined in paragraphs 6 and 7 are preparatory to the calibration
process. Personnel should become familiar with the entire section before beginning the
calibration.
b. Items of equipment used in this procedure are referenced within the text by common
name as listed in table 2.
c. Unless otherwise specified, verify the result of each test and, whenever the test
requirement is not met, take corrective action before continuing with the calibration.
Adjustments required to calibrate the TI are included in this procedure. Additional
maintenance information is contained in the manufacturers' manuals for this TI.
d. When indications specified in paragraphs 8 through 11 are not within tolerance,
perform the power supply check (paragraph 12) prior to making adjustments. After
adjustments are made, repeat paragraphs 8 through 11. Do not perform power supply
check if all other parameters are within tolerance.
e. Unless otherwise specified, all control and control settings refer to the TI.
7. Equipment Setup
WARNING
HIGH VOLTAGE is used or exposed during the performance of
this calibration.
DEATH ON CONTACT may result if
personnel fail to observe safety precautions.
REDUCE
OUTPUT(S) to minimum after each step within the
performance checks where applicable.
a. Remove TI protective cover as required for adjustments.
b. Install TI plug-in (model 3444A or 3445A) into TI main frame (model 3440A).
c. If necessary, set the TI 115-220 V LINE SELECTOR switch, located on rear panel,
to 115 V.
d. Connect TI to autotransformer.
e. Connect autotransformer to ac power source and adjust for 115 V output.
f. Turn TI on and adjust the SAMPLE RATE control to the desired rate, and allow at
least 30 minutes for warm-up.
