TB 9-6625-2352-35
Table 11b. Simpson, Model 270 Dc Voltage
Calibration Performance Limits and Adjustments
Dc Voltage
Test instrument
Calibrator output
Test instrument
1
Dc volts
Indication
Initial
Limits
range
(V)
output (V)
Min
Max
Adjustments
2.5
2.5
2.5
2.45
2.55
10
10
10
9.80
10.2
50
50
50
49
51
None
250
250
250
245
255
1000
1000
1000
970
1030
5000
5000 (900)
5000 (900)
4850 (750)
5150 (1050)
2
TI must be calibrated in horizontal position.
1
Replace calibrator with power supply. Move positive lead to TI D.C. 5000 V input. Calibrate at 900 V if power supply not
2
available. After 5000 V check is complete, reduce output to minimum replace power supply with calibrator and move positive
lead to TI + input.
Table 11c. Simpson, Model 270 Ac voltage
Calibration Performance Limits and Adjustments
Ac voltage
Test instrument
Calibrator
Test instrument
1
Ac volts
Indication
Initial output
err indication
Adjustments
range
(V)
(V)
(Hz)
(%)
250
250
250
60
3
R31 (R)
2.5
2.5
2.5
60
3
R28 (R)
10
10
10
60
3
----
50
50
50
60
3
----
1000
1000
1000
60
3
----
5000
900
900
60
22.2
----
2
TI must be calibrated in horizontal position.
1
Reduce output to minimum and move positive lead from TI + input to TI 5000 V DC/AC input. After 5000 V check is
2
complete, reduce output to minimum and move positive lead to TI + input.
Table 11d. Simpson, Model 270 Resistance
Calibration Performance Limits and Adjustments
Resistance
Test instrument1
Resistance standard indications
Test instrument
(Ω)
Indications
Resistance
ohms scale
Min
Max
Adjustments
(Ω)
range
2
RX1
12
11.1
13.0
RX100
12
1110
1300
None
RX10,000
12
111,000
130,000
TI must be calibrated in horizontal position.
1
2 Short
leads and adjust OHMS ADJ for a 0 indication on ohms scale. Repeat for each range.
22
