system is the most common method of measuring radio audiences worldwide. Some countries have introduced electronic devices called audiometers. RAJAR has tested several audiometers but has not determined any viable for introduction in the UK market. RAJAR continues to work with developers to determine future viability of innovations with audiometers and any new measurement techniques that could be of use.

Historically, the data has been collected from respondents via a paper diary. From quarter 3, 2011 RAJAR introduced an online version