Information

15 | Keysight | U1280 Series Handheld Digital Multimeters – Data Sheet
Frequency counter specification for U1282A
3
Division Range Resolution Accuracy Sensitivity
1
Minimum input frequency
1 99.999 Hz 0.001 Hz 0.02 % + 5
2
30 mV 0.5 Hz
999.99 Hz 0.01 Hz 0.002 % + 5 30 mV
9.9999 kHz 0.0001 kHz 0.002 % + 5 30 mV
99.999 kHz 0.001 kHz 0.002 % + 5 30 mV
999.99 kHz 0.01 kHz 0.002 % + 5 200 mV
9.9999 MHz 0.0001 MHz 0.002 % + 5, < 1 MHz 200 mV
100 9.9999 MHz 0.0001 MHz 0.002 % + 5, < 20 MHz 330 mV 1 MHz
99.999 MHz 0.001 MHz
Notes
1. The sensitivity is specified as input with a load of 50 Ω.
2. The frequency measurement is susceptible to error when measuring low-voltage, low-frequency
signals. Shielding inputs from external noise pickup is critical for minimizing measurement errors.
For non-square wave signal, add additional 5 counts.
3. The maximum measurement level is ± 1.8 Vp.
Square wave output specification
1
for U1282A
2,3
Output Range Resolution Accuracy
0.5, 1, 2, 5, 6, 10,15, 20, 25, 30, 40, 50, 60, 75, 80 Hz 0.01 Hz 0.005 % + 2
100, 120, 150, 200, 240, 300, 400, 480, 600, 800 Hz 0.1 Hz
1200, 1600, 2400, 4800 Hz 1 Hz
Duty cycle
1
0.390 % to 99.609 % 0.390625 % 0.4 % at full scale
Pulse width
1
1 / frequency Range / 256 Range / 256 + 2 µs
Amplitude Fixed + 2.2 V 0.1 V 0.2 V
Notes:
1. The specification is typical performance.
2. The positive or negative pulse width must be greater than 2 µs for adjustment of the duty cycle or
pulse width under different frequencies. Otherwise, the accuracy and range will be different from the
specification defined.
3. Output impedance: 600 Ω (nominal)
Multimeter data refresh rate
Function Slow (times/second) Fast (times/second)
ACV (V or mV) 5 40
DCV (V or mV) 5 40
Ω 5 40
Diode 5 40
Capacitance 1 (< 100 µF) —
DC µA, mA or A 5 40
AC µA, mA or A 5 40
Temperature 5 40
Frequency 1 (> 10 Hz) —
Duty cycle 1 (> 10 Hz) —
Pulse width 1 (> 10 Hz) —