How alarms work
How the device warns of radiation hazards
Alarm sources: the current count rate value, the current dose rate value, the accumulated dose. Each source has three alarm thresholds.
If the current count rate, dose rate or dose value crosses any of the thresholds from below, an Alarm Event occurs: first threshold — Alarm 1; second threshold — Alarm 2; upper limit of the scale — Over-range.
The first and second level thresholds are set in the settings for each source and can be changed at your discretion. The third threshold — the upper limit of the scale — cannot be changed via the menu.
The device constantly compares the current count rate, dose rate and accumulated dose values with the thresholds. Exceeding any of them puts the device into the Alarm State.
Each Alarm Source defines one of 4 states:
- Normal — value below the first threshold (no alarm)
- Alarm 1 — value above the first threshold but not above the second
- Alarm 2 — value above the second threshold but not above the third
- Over-range — value above the third threshold, beyond the scale
Exceeding the upper count rate threshold makes the dose rate estimate unreliable. In this case the upper dose rate threshold is also considered exceeded.
When any dose rate, count rate or accumulated dose threshold is exceeded, the alarm is activated: if enabled, the device vibrates and emits the alarm sound. To turn off the signal, acknowledge it with a short press on the round button — the device continues to show the exceedance with a flashing icon. An accumulated dose alarm stops only when the dose is reset or its threshold is changed.
Each Alarm Event has Alarm Signals: a sound signal and a vibration signal. They can be turned on and off in the settings independently — for each level of any source. Stop the signal with a short press on the round button; it sounds again at the next Alarm Event.
The Alarm State is indicated by:
- Red LED flashes
- Alarm icons in the display status bar
- The unacknowledged alarms status line
| Icon | Description |
|---|---|
| Count Rate Alarm 1 |
| Count Rate Alarm 2 |
| Count Rate over-range |
| Dose Rate Alarm 1 |
| Dose Rate Alarm 2 |
| Dose Rate over-range |
| Dose Alarm 1 |
| Dose Alarm 2 |
| Dose over-range |
Light signals can be turned on/off in the settings.
Behaviour with locked buttons:
If the device is locked and alarm indication (sound and/or vibration) is enabled, after thresholds are exceeded the display shows a line of the maximum recorded levels of unacknowledged alarms:
Rules for indicating alarm states and events on the display:
- If the swing buttons are locked, the status bar shows the message “Alarms:” and the icons of the maximum alarm levels reached from the moment the buttons were locked until now — one icon for each source
- A long press on the round button acknowledges viewing the list of maximum alarm levels; the swing buttons are unlocked and the normal status bar is displayed
- If Alarm Events occurred while the menu was displayed, then on exiting the menu the display shows the list of maximum alarm levels described above. The swing buttons are then locked
- If the swing buttons are unlocked and the display shows one of the display modes, the status bar shows the current alarm level icons for each source, alternating
Updated: Sep 22, 2026