The HFS-P3 Dosimeter has a built-in dose and dose rate alarm for radiation. The values for the alarm can be changed.
First, we will turn the device on by holding the "power button" (⏻) until the screen turns on.
Right after turning on, the device will show the current live dose rate and will be locked (note the padlock (🔒) icon next to the battery meter). This prevents alarm values from being changed. In order to unlock the device, we will hold both buttons down for a few seconds until the padlock icon(🔒) disappears.
In order to do this we will press the "menu button" (▼) until we get to the "Dose rate alarm" setting.
On the "Dose rate alarm" setting, we will tap the "power button" (⏻). This will cause the value to flash indication, we can now change it.
To change it, we will press the menu button" (▼) and it will cycle through available values between 0.6-300µSv.
Then we will set it by tapping the "power button" (⏻) again.
The value should have stopped flashing.
By tapping the menu button" (▼) we should get to the "Dose Alarm"
We can change it between 1-3000µSv by following the same method as before.
Now the alarms should be set.
Setting the dose rate above 3 uSv/h should prevent the alarm from triggering on planes