Standard Test Source

The potassium chloride Standard Test Source enables science departments to check the performance of GM tubes and counting equipment by measuring comparative detector beta efficiency.

Each test source contains a precisely measured 300 mg disc of pure, laboratory-grade potassium chloride, sealed within a durable transparent acrylic slide. The naturally occurring potassium-40 (K-40) present in potassium chloride provides a consistent, low-level beta radiation source suitable for routine GM tube performance checks.

Regular testing ensures that schools maintain confidence that their radiation detection equipment is operating correctly, supporting both safe practice and reliable experimental results. The source is suitable for use with GM tubes following the procedures outlined in CLEAPSS document L093.

Due to the extremely low activity of naturally occurring potassium compounds, this test source is not legally defined as a radioactive source and should not be stored, labelled or managed as one.

The product image is for illustrative purposes only. Please refer to the product description and technical specifications for accurate product information.