Agilent Technologies U1253A User's And Service Manual page 195

Table 7-1 DC accuracy
Function
500.00 μA
DC current
5000.0 μA
50.000 mA
440.00 mA
5.0000 A
10.000 A
500.00 Ω
[8]
Continuity
[9] [12]
Diode test 3.0000 V
[1]
Input impedance: > 1 GΩ for 50 mV to 100 mV ranges. Input impedance is 1.1 MΩ (nominal) in parallel with 1.1 MΩ at dual
display.
[2]
The accuracy could be 0.05%+5; always use the NULL function to zero out thermal effect (short test leads) before
measuring the signal.
[3] The accuracy of 500 Ω and 5 kΩ is specified after applying the NULL function, which is used to subtract the test lead
resistance and the thermal effect.
[4]
For the range of 50 MΩ, the relative humidity is specified for < 60%.
[5]
The accuracy is specified for < 50 nS, after applying the NULL function with open test lead.
[6]
Always use the NULL function to zero out thermal effect with open test leads before measuring the signal. If NULL function
is not used, an additional 20 counts need to be added to the accuracy. Thermal effect could occur due to the following:
• Wrong operation — where the resistance, diode, or mV measurement function is used to measure high voltage signals
within the range of 50 V to 1000 V.
• After battery-charging has completed.
• After measuring a current greater than 500 mA, it is recommended that the meter be left to cool down for twice the
measurement time used.
[7]
Current can be measured up to 10 A continuously. An additional 0.5% needs to be added to the specified accuracy if the
signal measured is in the range of 10 A to 20 A for 30 seconds maximum. After measuring a current of > 10 A, leave the
meter to cool down (in switched OFF state) for twice the measurement time used, before using it again to make low-current
measurement.
U1253A User's and Service Guide
± (% of reading + number of LSD)
[10]
Range
0.01 μA
0.1 μA
0.001 mA
0.01 mA
0.0001 A
[7]
0.001 A
0.01 Ω
0.1 mV
Test current or burden
Resolution
< 0.06 V (100 Ω)
0.6 V (100 Ω)
0.09 V (1 Ω)
0.9 V (1 Ω)
0.2 V (0.01 Ω)
0.4 V (0.01 Ω)
1.04 mA
1.04 mA
Specifications
voltage Accuracy
[6]
0.05+5
[6]
0.05+5
[6]
0.15+5
[6]
0.15+5
0.30+10
0.30+5
0.05+10
0.05+5
7
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