ABSTRACT
The 'radiation measurement' mainly refers to 'absolute' measurement of ionising radiation and not to the whole spectrum of radiation measuring devices. These include the Geiger counter, and the rectilinear scanner and Anger gamma camera which are dependent upon a sodium iodide scintillation detector. The first proposal for a gamma-ray unit was based on a comparison between the radiation emitted by the radium source and that emitted by a source of uranium. Film blackening as a method of dose measurements had a renaissance from the late 1940s to the late 1980s when, with small ionisation chambers designed for pocket wear, it was a main method of measuring the external radiation received by radiation workers. The most well known radiation unit depending upon a chemical colour change subsequent to exposure to radiation was the 'pastille unit' or 'B unit' of Sabouraud and Noire in 1904 who used a small capsule of platino-barium cyanide.
