Input Speciications

The accuracy is given as ± (% of reading + counts of least signiicant digit (LSD)) at 23 °C ± 5 °C, with relative humidity less than 80%

R.H. and after a warm-up period of at least ive minutes. Without warm-up, an additional ive counts of LSD need to be considered.

Voltage speciications

Function

Range

Resolution

Accuracy

Overload protection

50 mV

1 µV

250 Vrms

500 mV

10 µV

0.03% + 5

5 V

0.1 mV

50 V

1 mV

250 V

10 mV

(True-rms: From 5% to 100% of range)

50 mV

1 µV

45 Hz to 5 kHz: 0.7% + 40

5 kHz to 20 kHz: 1.5% + 40

500 mV

10 µV

45 Hz to 5 kHz: 0.7% + 20

5 kHz to 20 kHz: 1.5% + 20

5 V

0.1 mV

50 V

1 mV

250 V

10 mV

(True-rms: From 5% to 100% of range)

50 mV

1 µV

45 Hz to 5 kHz: 0.8% + 70

5 kHz to 20 kHz: 1.6% + 70

500 mV

10 µV

45 Hz to 5 kHz: 0.8% + 25

5 kHz to 20 kHz: 1.6% + 25

5 V

0.1 mV

50 V

1 mV

250 V

10 mV

1.

Input impedance: 10 MΩ (nominal) for the range of 5 V and above, and 1 GΩ (nominal) for the 50/500 mV range.

2.

Accuracy can be improved to 0.05% + 5. Always use the Relative function to offset thermal effects before measuring the signal.

3.

Input impedance: 1.1 MΩ in parallel with < 100 pF (nominal) for the range of 5 V and above, and 1 GΩ (nominal) for the 50/500 mV range.

Crest factor ≤ 3.

Current speciications

Function

Range

Resolution

Accuracy

Burden

voltage/shunt

Overload protection

DC current

50 mA

1 µA

0.06 V (1 Ω)

250 V, 630 mA

Quick acting fuse

500 mA

10 µA

0.6 V (1 Ω)

(True-rms: From 5% to 100% of range)

50 mA

1 µA

45 Hz to 5 kHz: 0.6% + 20

0.06 V (1 Ω)

500 mA

10 µA

45 Hz to 5 kHz: 0.6% + 20

0.6 V (1 Ω)

(True-rms: From 5% to 100% of range)

50 mA

1 µA

45 Hz to 5 kHz: 0.7% + 25

0.06 V (1 Ω)

500 mA

10 µA

45 Hz to 5 kHz: 0.7% + 25

0.6 V (1 Ω)

1.

Always use the Relative function to offset thermal effects before measuring the signal. If this function is not used, accuracy could go down to 0.03% + 25.

Thermal effects may be present due to:

– Constant current, constant voltage, or square wave output.

– Wrong operation. For example, resistance, diode, or mV measurement function is used to measure high voltage signals exceeding 250 V.

– After battery charging has completed.

– After measuring current greater than 50 mA.

2.

Crest factor ≤ 3.

04 | Keysight | U1401B Handheld Multi-function Calibrator/Meter - Data Sheet