GammaTest C/GammaTest F

Dose rate alarm unit

GRAETZ GammaTest C with four adjustable alarm thresholds
GRAETZ GammaTest F with alarm threshold at 25 µSv/h


Fields of application

Fire Brigades, Civil Defence



The GammaTest is a light, robust battery operated pocket-sized dose rate alarm unit for the personal radiation protection and for the detection
of gamma and X-rays. The GammaTest C has four adjustable alarm thresholds.  When being exceeded, an optical (red LED) and acoustic alarm will be triggered. Values below are shown by the red LED signalizing an increase or
decrease of dose rate as optical single pulses by changing the flash frequency.

The dose rate alarm threshold 25 µSv/h is required by the German Fire Brigades Regulation (FwDV 500) for the determination of a danger zone.

The alarm threshold 40 µSv/h is required in the range of non-destructive testing (NDT) during radiographic processing (for example by X-rays): the local dose rate outside the control area may not exceed 40 µSv/h.

The splashproof, anodized aluminium housing of the GammaTest ensures a shielding against EMC influence.

The version GammaTest F is especially designed for German Fire Brigades: only one alarm threshold at 25 µSv/h relevant for Fire Brigade operations, thus excluding operating errors.


Technical Data

Detector energy compensated GM tube
Measurand ambient dose rate equivalent Ḣ*(10)
Energy range 40 keV up to 1.3 MeV
Alarm thresholds

GammaTest C
25 µSv/h, 40 µSv/h, 1 mSv/h, 10 mSv/h

GammaTest F
25 µSv/h

Overload capacity > 500 mSv/h
Temperature range -30°C up to +60°C (operation)
-40°C up to +70°C (storage)
Power supply 2 × AAA 1.5 V (LR03)
Operating life approx. 250 hours
Acoustic alarm > 80 dB(A) measured in 30 cm distance

(106 × 67 × 23) mm, without clip
190 g (with batteries)