ECOTEST TERRA-P MKS-05 Operating Manual page 36

If the THRESHOLD button is pressed for more than two seconds, the low-order
digit starts blinking, indicating that a new threshold level value can be programmed.
A two-tone audio signal indicates that the programmed DER threshold level has
been exceeded.
Note 1. Audio signaling of registered gamma quanta is switched on automatically
along with the dosimeter. Extinction of the digital LCD automatically switches off
audio signaling of registered gamma quanta.
Note 2. Audio alarm of exceeded programmed DER threshold level is
independent of the status of audio signaling system of registered gamma quanta.
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