Primary AC Voltage Standard Calibration of Audio Source

Keysight Technologies UK Ltd

National Physical Laboratory
Round 3

Keysight Technologies has for many years produced audio test products.

These in general will include an audio source and an audio analyzer.

The audio market itself is characterized by: 1) the audio frequency range; and 2) the fidelity of the measurement requirements, reflected in the dynamic range and accuracy.

The absolute accuracy of the audio generator is a specified parameter of most products in this category.

Its accuracy is specified generally in term approaching <1, however this has never been achieved before.

Furthermore, the output fidelity of an audio source is also reflected in its harmonic content, often referred to in terms of Total Harmonic Distortion (THD) or Total Harmonic Distortion plus Noise (THDN).

Due to the very low levels of distortion present in an audio source it is inherently difficult to establish a fully traceable measure of THD.

Methods built around quantum standards that are independently verifiable as perfectly linear will enable traceable measurements of THD and open the door to new applications.

In attempting to solve these fundamental problems the team will make a step change in the performance of audio signal analyzers.

This in turn will open the door to new applications, particularly in propagating the accuracy of quantum voltage standards to industrial and commercial applications.

Analysis for Innovators