Technical data

160 Agilent U1251B/U1252B User’s and Service Guide
7 Specifications
Function Range Resolution
Test Current/
Burden Voltage
Accuracy
U1251B U1252B
Current
500.00 µA 0.01 µA 0.06 V 0.1 + 5
[7]
0.05 + 5
[7]
5000.0 µA 0.1 µA 0.6 V 0.1 + 5
[7]
0.05 + 5
[7]
50.000 mA 0.001 mA 0.09 V 0.2 + 5
[7]
0.15 +5
[7]
440.00 mA 0.01 mA 0.9 V 0.2 + 5
[7]
0.15 + 5
[7]
5.0000 A 0.0001 A 0.2 V 0.3 + 10 0.3 + 10
10.000 A
[8]
0.001 A 0.4 V 0.3 + 10 0.3 + 5
Notes for current specifications:
7 Always use the Null function to zero out thermal effect with open test lead before measuring the signal. If the Null
function is not used, add 20 counts to the specified 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 is complete.
• After measuring a current greater than 440 mA, it is recommended that the meter be left to cool down for twice the
length of measurement time used.
8 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 30 seconds maximum. After measuring current > 10 A, leave the meter to
cool down (in switched OFF state) for twice the length ofmeasuring time used before application of low current
measurement.
Function Range Resolution
Test Current/
Burden Voltage
Accuracy
U1251B U1252B
Diode
[9][10][11]
- 0.1 mV 1.04 mA 0.05 + 5
Notes for diode specifications:
9 Overload protection: 1000 Vrms for short circuits with < 0.3 A of current.
10 Built-in buzzer beeps continuously when the voltage measured is less than 50 mV, and beeps once for forward-based
diodes or semiconductor junctions measured between 0.3 V and 0.8 V (0.3 V ≤ reading ≤ 0.8 V).
11 Open voltage for diode: < + 4.2 V DC.
Table 7-1 DC Accuracy ± (% of reading + Number of Least Significant Digit) (continued)