2015

The Keithley 2015 Series total harmonic distortion and audio analyser multimeters combine audio band quality measurements and analysis with a broad purpose 6.5 digit DMM—all in one half-rack instrument. They can measure total harmonic distortion (THD) over the complete 20Hz to 20kHz audio band and can compute THD+Noise and signal-to-noise plus distortion (SINAD). The 2015‑P and 2016-P directly identify peak values of the frequency spectrum.

Frequency Domain Distortion Analysis

For applications such as assessing non-linear distortion in components, devices, and systems, DSP-based processing allows Keithley 2015 provide frequency domain analysis in conventional time domain instruments. The 2015 DMM can measure Total Harmonic Distortion (THD) over the complete 20 Hz to 20 kHz audio band. The 2015 Digital Multimeter can also measure over a wide input range (up to 750 Vrms) and have low residual distortion (–87 dB). The THD reading can be expressed either in decibels or as a percentage.

In addition to THD, the Keithley 2015 can compute THD+Noise and Signal-to-Noise plus Distortion (SINAD). For analyses in which the individual harmonics are the criteria of greatest interest, the instruments can report any of the (up to 64) harmonic magnitudes that can be included in the distortion measurements. The user can program the actual number of harmonics to be included in a computation, so accuracy, speed, and complexity can be optimised for a specific application.

Optimised for Production Testing

The Keithley 2015 THD performs fast frequency sweeps for characterising audio-band circuitry in production test systems. For example, the instrument can execute a single sweep of 30 frequencies and transmit both rms voltage readings and THD readings to a computer in only 1.1 seconds. With that data, a complete frequency response analysis and a harmonic distortion vs. frequency analysis can be performed in a very short time.

With the 2015 THD DMM, which is optimised for production testing, test engineers can lower test times, in comparison to test speeds achievable with general-purpose audio analysers, without sacrificing production test quality.