Keysight 331A Distortion Analyzer

Manufacturer: Keysight
Model Number: 331A
The HP 331A distortion analyzer is a solid state instrument for measuring distortion and AC voltages. Distortion levels of 0.1% to 100% full scale are measured in seven ranges for any fundamental frequency from 5 Hz to 600 kHz. Harmonics are indicated up to 3 MHz. The distortion characteristics can be monitored at the OUTPUT connectors with an oscilloscope, a TRMS voltmeter, or a wave analyzer. The voltmeter inside the 331A can be used separately for general purpose voltage and gain measurements.


  • Distortion measurement range: 5 Hz to 600 kHz
  • Distortion measurement accuracy: Distortion levels of 0.1% to 100% full scale are measured in seven ranges for frequencies of 5 Hz to 600 kHz
  • Frequency calibration accuracy: Better than ±5% from 5 Hz to 300 kHz; better than ±10% from 300 kHz to 600 kHz
  • Input impedance: 1 M
  • Input level for distortion measurements: 0.3 Vrms for 100% set level or 0.245 V for 0 dB set level (up to 300 V may be attenuated to set level reference)
  • DC isolation: Signal ground can be ±400 Vdc from external chassis
  • Voltmeter range: 300 µV to 300 Vrms full scale (13 ranges) 10 dB per range
  • Voltmeter accuracy: ±2%, ±5% depending on voltage range and frequency
  • Voltmeter frequency range: 5 Hz to 3 MHz
  • Voltmeter residual noise measurements: <25 µVrms or <30 µVrms depending on termination
  • Output: 0.1 Vrms ±0.01 Vrms and 0.05 Vrms ±0.005 V into 2 k? for full scale meter deflection

Option 01 meter with VU characteristics meets FCC requirements for AM, FM, and TV broadcasting


10 lb.

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