Instruments used for radiation measurement fall
into two broad categories:
- rate measuring instruments and
dose measuring instruments.
Rate measuring instruments measure the rate at which
exposure is received (more commonly called the radiation intensity). Survey meters, audible alarms and area monitors fall into this
category. These instruments present a radiation intensity reading relative to time, such as R/hr or mR/hr. An analogy can be made between these instruments and the speedometer of a car because both are measuring units relative to time.
Dose measuring instruments are those that measure
the total amount of exposure received during a measuring period. The dose measuring instruments, or dosimeters, that are commonly
used in industrial radiography are small devices which are designed
to be worn by an individual to measure the exposure received by the individual. An analogy can be made between these instruments and the odometer of a car because both are measuring accumulated units.
The radiation measuring instruments commonly used in industrial radiography are described in more detail in the following