Specifications

3
FUNCTION RANGE RESOLUTION TEST CURRENT/
BURDEN VOLTAGE
ACCURACY ± (% of reading + No. of Least Significant Digit)
U1251A/U1251B U1252A/52B/53A/53B
VOLTAGE
(1)
50.000 mV 0.001 mV - 0.05 + 50
[2]
0.05 + 50
[2]
500.00 mV 0.01 mV -
0.03 + 5
0.025 + 5
1000.0 mV 0.1 mV -
5.0000 V 0.0001 V -
50.000 V 0.001 V -
500.00 V 0.01 V -
0.03 + 5
1000.0 V 0.1 V -
RESISTANCE
(8)
500.00 W
[3]
0.01 W
1.04 mA 0.08 +10 0.05 + 10
5.0000 kW
[3]
0.0001 kW
416 µA
0.08 + 5 0.05 + 5
50.000 kW 0.001 kW
41.2 µA
500.00 kW 0.01 kW
4.12 µA
5.0000 MW 0.0001 MW
375 nA
0.2 + 5 0.15 +5
50.000 MW
[4]
0.001 MW
187 nA
1 + 10 1 + 5
500.00 MW
[4]
0.01 MW
187 nA
N/A
3+10 < 200 MW / 8+10 > 200 MW
500.00 nS
[5]
0.01 nS 187 nA 1 + 20 1 + 10
CURRENT
500.00 µA 0.01 µA
0.06 V (100 W)
0.1 + 5
[6]
0.05 + 5
[6]
5000.0 µA 0.1 µA
0.6 V (100 W)
50.000 mA 0.001 mA
0.09 V (1 W)
0.2 + 5
[6]
0.15 + 5
[6]
440.00 mA 0.01 mA
0.9 V (1 W)
5.0000 A 0.0001 A
0.2 V (0.01 W)
0.3 + 10
0.3 + 10
10.000 A
[7]
0.001 A
0.4 V (0.01 W)
0.3 + 5
DIODE TEST
(8)
- 0.1 mV 1.04 mA 0.05 + 5
DC SPECIFICATIONS
[1] Input impedance: Refer to Table A on page 8.
[2] The accuracy could be 0.05% + 10 for U1251A and 0.05% + 5 for U1252A/3A. Always use the NULL function to zero out the thermal effect before measuring the signal.
[3] The accuracy of 500 W and 5 kW is specified after NULL function, which is used to subtract the test lead resistance and the thermal effect.
[4] For the range of 50 MW and 500 MW, the R.H. is specified for <60%.
[5] The accuracy is specified for <50 nS and after NULL function with open test lead.
[6] 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, an additional 20 counts
needs to be added to the DC current accuracy. Thermal effect could occur due to the following:
• Wrong operation to measure the high voltage of 50 V ~ 1000 V for resistance, diode, and mV measurements.
• After battery-charging has completed.
• After measuring a current greater than 440 mA, it is suggested that the meter be left to cool down for twice the measuring time used.
[7] Current can be measured up to 10 A continuously. An additional 0.5% needs to be added to the specied accuracy if the signal measured is in the range of 10 A~20 A
for 30 seconds maximum. After measuring a current of > 10 A, leave the meter to cool down for twice the measuring time used before application of low current
measurement.
[8] Maximum open voltage: <+ 4.2V.
U1251A/U1251B AC SPECIFICATIONS
FUNCTION RANGE RESOLUTION
ACCURACY ± (% of reading + No. of Least Significant Digit)
FREQUENCY
30 Hz ~ 45 Hz 45 Hz ~ 1 kHz 1 kHz ~ 10 kHz 10 kHz ~ 30 kHz
TRUE RMS AC
VOLTAGE
[1] [2]
50.000 mV 0.001 mV
1.0+60
0.6+40
1.0+40 1.6+60
500.00 mV 0.01 mV
0.6+25
1000.0 mV 0.1 mV
1.0+25
1.6+405.0000 V 0.0001 V
50.000 V 0.001 V
500.00 V 0.01 V 1.6+40
[3]
1000.0 V 0.1 V 0.6+40 1.0+40 N/A