Agilent Technologies U1251A, Руководство пользователя и сервисное руководство

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Performance Tests and Calibration 7
Agilent U1251A/U1252A User’s and Service Guide 137
[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 5k
W
is specified after NULL function.
[4] For range of 50 M
W
, the RH is specified for < 60%.
[5] The accuracy is specified for < 50nS 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 NULL mode to zero residual
[8] The accuracy does not include the tolerance of thermocouple probe.
The thermal sensor plugged into the meter should be placed in the
operating enviroment for at least an hour.
Use Null function to reduce the thermal effect.
[9] Always use relative function to zero thermal effect with open test lead
before measuring the signal.
If you do not use Relation function, add 20 digits for accuracy
purposes.
[10] 10A continuous, and additional 0.5% to specified accuracy when
measuring a signal greater than 10 A~20 A for 30 seconds maximum.
After measured current for > 10 A, to cool down the meter for twice
the measuring time you applied before low current measurement.
[11] The current can be measuring from 2.5A to 10A continuous, and the
additional of 0.5% to specified accuracy as measure the signal
greater than 10A~20A for 30 seconds maximum.
After measured current for > 10A, to cool down the meter for 2 times
of measuring time you applied before low current measurement
[12] For signal frequency greater than 1 kHz, additional 0.1% per kHz to be
added to accuracy