134
Keysight U1251B/U1252B User’s and Service Guide
6
Performance Tests and Calibration
Notes for verification test:
1
The additional error to be added as frequency > 20 kHz and signal input < 10% of range: 300 counts of LSD per kHz.
2
The accuracy could be 0.05% + 10, always use relative function to zero thermal effect (short test leads) before measuring
the signal.
3
The accuracy of 500
W
and 5 k
W
is specified after the Null function.
4
For range of 50 M
W
/500 M
W
, the RH is specified for < 60%.
5
The accuracy is specified for < 50 nS and after Null function as open test lead.
6
All frequency counters are susceptible to error when measuring low voltage, low-frequency signals. Shielding inputs from
external noise pickup is critical for minimizing measurement errors.
7
Use the Null mode to zero residual.
8
The accuracy does not include the tolerance of the thermocouple probe. The thermal sensor plugged into the meter should
be placed in the operating enviroment for at least an hour. Use the Null function to reduce the thermal effect.
9
Always use relative function to zero the thermal effect with open test lead before measuring the signal. If you do not use
Relation function, add 20 digits for accuracy purposes.
Step
Test Function
Range
5520A Output
Error from nominal 1 year
U1251B
U1252B
19
Press
button to go to
A mode
5 A
5 A, 1 kHz
± 42 mA
± 37 mA
3A
3 A, 5 kHz
± 96 mA
± 96 mA
10 A
[
11
]
10 A, 1 kHz
± 100 mA
± 90 mA
Square Wave
Output
Use 53131A
20
Turn the rotary switch to the
position
120 Hz @ 50%
N/A
± 26 mHz
4800 Hz @ 50%
N/A
± 260 mHz
Duty Cycle
100 Hz @ 50%
N/A
± 0.398%
[
12
]
100 Hz @ 25%
N/A
± 0.398%
[
12
]
100 Hz @ 75%
N/A
± 0.398%
[
12
]
Use 34410A
Amplitude
4800 Hz @
99.609%
N/A
± 0.2V