Survey meter

The hand-held survey meter is probably the most familiar radiation measuring device owing to its wide and visible use.

The instruments are designed to be hand-held, are battery powered and of low mass to allow easy manipulation.

This is usually the “click” associated with the Geiger type instrument, and can also be an alarm warning sound when a rate of radiation counts or dose has been exceeded.

This gives the operator rapid feedback on both the level of radiation and the type of particle being detected.

These features allow the user to concentrate on manipulation of the meter whilst having auditory feedback of the rate of radiation detected.

This latter is preferred for checking of convoluted surfaces for radioactive contamination due to the ease of manipulating the probe.

However, scintillation probes can be affected by high gamma background levels, which must therefore be checked by the skilled operator to allow the instrument to compensate.

A common technique is to remove the counter from any proximity to alpha and beta emitters and allow a "background" count of gamma.

Hand-held ion chamber survey meter in use to detect gamma radiation
Alpha scintillation probe under calibration
Survey meters in use in an extreme environment
"hotspot" detector on long pole being used for detecting gamma
Ion chamber type survey meter showing beta radiation sliding absorption shield withdrawn to allow beta detection
Large area scintillation probe being used to measure surface radioactive contamination. The probe is held as close to the surveyed object as practicable