The displayed value of the unit sensors has to be checked with a comparative measurement with a reference radiometer. The value measured with the unit's UV sensor may not exceed more than 5% above the valued measured with the reference radiometer. This value should also not be significantly below the value reduced by the measuring uncertainty. If this is case, the cause has to be determined and eliminated (soiling). If necessary, the UV sensor has to be replaced with another sensor with a valid calibration certificate; the new sensor then has to be checked and recalibrated by an approved organization.

The comparative measurement with a reference radiometer takes place when the unit is in operation. The lamps must be on for at least 15 minutes without interruption.

Keep in mind the following instructions are meant to be a general guideline. Always refer to the owner's manual for your specific UV system.

Enable the "Test mode" function in the operator menu

For the duration of the check/control measurement (set at factory to 120 s), the alarm or switching functions are disabled.

Unscrew the union nut from the measuring glass

Pull the UV sensor out

Insert reference sensor and check displayed value

Put the unit's UV sensor back in

Screw the union nut into place

Alarm or switching functions are Now enabled

After the test time of 120 S has expired.