TB 9-6625-2146-35
Table 5. Ac Voltage continued - Continued.
Ac voltage standard indications (V ac)
Weston, Model 749
General Electric, Model
400 Hz Only
AK-4, Weston, Models 749
ME-79/USM-33
and 633-VA1 at
Test
ME-79A/USM-33
60 Hz only
instrument
Weston, Model 528
50 to 1000 Hz
ME-489/U
range
25 to 125 Hz
2%
3%
5%
Min
Max
Min
Max
Min
Max
20
---
---
---
---
---
---
30
---
---
---
---
---
---
50
---
---
---
---
---
---
60
---
---
---
---
---
---
75
---
---
---
---
---
---
125
---
---
---
---
---
---
150
147
153
145.5
154.5
142.5
157.5
175
---
---
169.75
180.25
---
---
250
---
---
---
---
---
---
300
294.0
306.0
291.0
309.0
285.0
315.0
350
---
---
339.5
360.5
---
---
400
---
---
---
---
---
---
450
---
---
---
---
---
---
600
588.0
612.0
582.0
618.0
570.0
630.0
700
---
---
679.0
721.0
---
---
750
---
---
727.5
772.5
---
---
11. Ac Amps
a. Performance Check
(1) Set TI function switch (if applicable) to ac current and set range switch to lowest
range.
(2) Connect equipment as shown in figure 2.
(3) Adjust precision oscillator (A10) frequency for 60 Hz and voltage output as
required to obtain full-scale indication on TI. Digital voltmeter (A9) will indicate within
limits specified under accuracy in table 6 for TI being calibrated.
(4) Repeat (3) above at low (50 Hz) and high (as Applicable) (1000 Hz maximum)
frequency listed for TI.
(5) Repeat technique of (1), (3), and (4) above for remaining ranges.
NOTE
Perform tracking and linearity check on a convenient range at
cardinal points approximately two-thirds and one-third of full
scale. Indications will be within stated percent of full scale
for each cardinal point.
b. Adjustments. No adjustments can be made.
12
