TB 9-4931-383-50
h. Connect operating voltage source (A5) to voltage regulator (A8), set its POWER
switch to STDBY/ RESET, and allow to warm up until called for.
i. It is necessary to know actual value of 1.018 + ∆E output of dc transfer standard
(A2) to complete this calibration. If calibration of dc transfer standard is no more than 10
days old, the value recorded at time of calibration is sufficient. If calibration is more than
10 days old, determine the value by performing (1) through (11) below:
NOTE
When adjusting for a null indication on null detector (A4),
always start on highest range of null detector and proceed
down range to required sensitivity. When reading is complete,
return null detector to high range.
(2) Adjust dc transfer standard (A2) for 1.018 + ∆E mean output and set ∆E dials to
last three digits of standard cell (A6) certificate value.
(3) Set voltage divider (A7) to one-tenth of value of dc transfer standard setting.
(4) Adjust TI for a nominal 10-volt output and set its POWER switch to OPR.
(5) Adjust TI voltage dials for a null indication on null detector (A4). Do not change
TI voltage dials until instructed.
(6) Set TI POWER switch to STDBY/RESET.
(7) Replace dc transfer standard with standard cell in equipment setup.
(8) Set TI POWER switch to OPR.
(9) Adjust voltage divider for a null indication on null detector.
Record voltage
divider indication.
(10) Set TI POWER switch to STDBY/RESET.
(11) Compute the actual value of the dc transfer standard output as follows. If in
step (9) above the voltage divider setting was increased, subtract the amount of change
multiplied by 10 from the standard cell value. If the setting was decreased, add the
amount of change multiplied by 10 to the standard cell value. Record the value for future
use.
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