This International Standard applies to portable instruments used for measuring the specific activity of beta-emitting radionuclides in food/foodstuffs and intended for operation under field conditions. This does not apply to low background laboratory instrumentation requiring highly skilled personnel. The instruments designed for measurement of beta contamination in foodstuffs under field conditions should not require special sample preparation other than machining (cutting, grinding, etc.). These instruments may be used in principle to measure beta emitting surface contamination and other radiation measurements as well, but these applications lie outside the scope of this standard. The same instruments intended for measuring foodstuffs can also be used for the measurement of environmental samples, such as soil, sewage, plant and animal life, etc. These instruments can be used to determine specific beta activity for a wide variety of samples under this standard. The purpose of this standard is to specify the main performance characteristics of instruments intended for measurement of specific activity of beta-emitting radionuclides in foodstuffs, their methods of testing and documentation requirements.