TB 9-6625-174-24
NOTE
Due to the Auto ranging features of some TIs and inherent
limitations of the coil, some Limits shown in appendix B may
not be equally distributed. For example: A Clamp Meter has a
specification of (3% of rdg + 5 dgts) with 2 ranges of display (a
999.9 A ac range and a 2500 A ac range). The check for the
999.9 A ac range is done at 900 A ac. The maximum value of
current to apply to the 2500 A ac range is 1000 A ac. The Limit
listed for the high side would be 1035 A ac. The Limit for the
low side would drop down on the 999.9 A ac range and would be
displayed as 969.5 A ac because of the 5-digit adder being
applied to the lower range.
NOTE
Coil should be constructed with 14 gage wire. Diameter of coil
should be about 4 inches. Fan out coil to 270 with spacing
0.375 inch (1 cm) using tape to maintain coil shape. These
dimensions are not critical, only a guide.
a. Using guidance in note above, construct a coil of desired number of turns.
b. Unless otherwise specified, center the Coil in the TI jaws while making A dc or A ac
measurements.
c. If applicable, ensure TI DATA HOLD switch is off during performance checks.
d. Zero TI range/function as necessary.
e. Throughout the performance checks, all reference to Range, Applied and Limits
columns are in reference to appendix B.
8. Dc Voltage
a. Performance Check
(1) Connect TI DC VOLTAGE terminals to calibrator OUTPUT terminals,
observing polarity.
(2) Set TI controls for the first range listed in the Range column. Some TIs require
the test leads be changed to different jacks for range changes.
(3) Set calibrator for the first value listed in the Applied column and set OPR/STBY
switch to OPR. If TI indication is not within limits specified, perform b below.
(4) Repeat technique of (2) and (3) above for remaining ranges and applied values
listed in Range and Applied columns. If TI indication is not within limits specified, perform
b below.
(5) If applicable, disconnect equipment setup.
b. Adjustments. Refer to TI manufacturer's manual for corrective action.
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