Simple Dosemeter - With Alarms

A simple dosemeter with alarms is defined as one which gives a numeric display of the accumulated dose to which the dosemeter is exposed and gives an alarm indication when a pre-set dose alarm level is exceeded.

Applications

• Dose response at low dose rate

Mount the dosemeter in the calibration orientation with its reference point at the point of test in an appropriate radiation field. Record the dosemeter response to a dose delivered at a rate of no more than 100 µSv h^-1. Pass/Fail Criteria: Agreement to within ± 30% of Type Test data.

• Dose response at high dose rate

Mount the dosemeter in the calibration orientation with its reference point at the point of test in an appropriate radiation field. Expose the dosemeter to a dose rate in

excess of that which it could reasonably encounter in practice, for at least 30 seconds, and record its response. A minimum dose rate of 10 mSv h^-1 should be used. Pass/Fail Criteria: Agreement to within ± 30% of Type Test data. Overload indication should operate if the maximum range of the dosemeter is exceeded.

• Background accumulation

The background-accumulated dose should be checked in an area known to have a low, stable, background dose rate.

• Response at or below minimum energy of interest

Mount the dosemeter in the calibration orientation with its reference point at the point of test in a 60 keV photon field and determine its response.

Filtered x-radiation from the ISO Low or Narrow series⁵may be used. If the dosemeter is expected to be used to monitor photons less than 60 keV, a test at a lower energy is necessary. Pass/Fail Criteria: Agreement to within ± 30% of Type Test data. 

• Directional Dependence

Mount the dosemeter in a 60 keV photon field as in the energy dependence test above. Determine its response at +60° and -60° about it’s reference point. Users may wish to use other angles between 45˚ and 60˚ if more appropriate for the

dosemeter type. Type Test data should be consulted and used to determine the most appropriate single angle. Pass/Fail Criteria: Agreement to within ± 30% of Type Test data.

• Alarm function

Dose: expose the dosemeter to a doses close to 85 % and then 115 % of the value at which the alarm has been set to trigger. For dosemeters with multiple

alarm levels the function of all alarms should be confirmed. For some applications it should also be confirmed that the alarm does not trigger too early. Pass/Fail Criteria: Alarm(s) should trigger only when the dose set level is exceeded appropriately.