Sect. IV Page 2 Model 412A
5) Check 412A reading versus Voltmeter Calibra-
tion Generator output on each 412A range. Maxi-
mum 412A error should be no greater than 1% of lo1
full scale.
NOTE
RESISTOR;
When checking 412Aon its .003and .001 volt ranges, SEE TABLE
set the selector switch of Voltmeter Calibration
Generator to OFF and note any 412A zero offset
due to thermoelectric voltage. Add or subtract, as
appropriate, any offset from the 412A reading when
Voltmeter Calibration Generator selector switch
is set to DC + .
---------------
Figure 4-1. Equipment Setup for Current Check
6) Check 412A meter tracking on + and - 1 volt
ranges. Maximum error should be no greater than
0.01 volt.
NOTE
7) Repeat step 5 (on one range only) at line volt-
age of 103 and 127 volts. Switching through the current ranges from 10 to
1000 does not change the current shunt. Only the
voltage attenuator, checked in part A above,
B. MILLIAMMETER CHECK changes. (See Figures 4-5, 4-6and 4-7 for simpli-
fied switching details.)
1) Set line voltage to 115 volts. -- -------------
2) Set FUNCTION selector to MA and POLARITY
switch to+ . C. OHMMETER CHECK
3) Connect 412A to Voltmeter Calibration Genera- 1) Set FUNCTION selector to OHMS.
tor as shown in Figure 4-1.
2) Connect 1% resistor of 1, 10, 100, 1000, 10K,
4) Check 412A as shown in Table 4-1. 100K, lM, 10M and lOOM ohms between MA/OHMS
TABLE 4-1. AMMETER CHECK
Output of Voltmeter Series Model 412A Model 412A Reading
Calibration Generator Resistance Range (+2% of full scale)
1 volt 1.OOM +O.l% .001 1 .o
3 volts 1.00M +O.l% .003 3.0
10 volts 1.00M +O.l% .01 1.0
30 volts 1.00M *O.l% .03 3.0
100 volts 1.00M *O.l% .1 1 .o
300 volts 1.00M *0.1% .3 3.0
300 volts 300K +O.l% 1 1 .o
300 volts lOOK +O.l% 3 3.0
300 volts 30K 50.1% (5 watts) 10 1 .o
300 volts 30K *0.1%(5 watts) 30 1.0 (on 0-3 scale) |
ACEC
