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Calibration
The ultraviolet meter can only be calibrated when the power switch is in the ON position and
the lamps are operational . Lamps must warm up for three minutes prior to any calibrations .
Recalibrate after the lamps have been operational for 100 hours; when the lamps are stable .
The board’s initial state will be in the fault state . The low UV light will be lit and the alarm will
sound and the relay will be in the normally open condition . The reason for this state is to allow for
lamp warm-up if the unit is equipped with a solenoid valve . If the unit is equipped with a solenoid
valve, the lamps will be on, but the coil in the solenoid will be de-energized for three minutes to
prevent water flow until the lamps are warmed up and to proper intensity .
After three minutes, the board will revert to the operational “normal” state . If the system is at or
above minimum intensity, the relay will revert to the normally closed position, the low UV light will
go off, the alarm stop sounding, and if equipped with a solenoid valve, the valve will open and
water will flow .
To calibrate the UV Monitor Board
NOTE: Many industrial applications do not require an audible alarm for low UV intensity . When
calibrating the UV monitor board, the alarm will sound during the warm-up period . To disable the
alarm, remove jumper JP13 located at the right edge of the board below the alarm .
Take caution when removing the jumper as exposed prongs may have voltage present!
1 . Calibration must be made with new lamps only .
2 . Lamps must be allowed to warm up for three minutes prior to any calibrations .
3 . Open the enclosure door to expose the display plate . On the right side of the display plate,
locate the Run potentiometer, the Set potentiometer, and the Cal switch .
4 . First set the trip level . Push and hold the Cal switch and adjust the Set potentiometer until
the display reads 85% . When the UV intensity falls below 85% the system will go into the fault
state . The UV unit is designed to provide proper UV dosage at 85% of original UV intensity .
With modern technology UV lamps, this should occur at about 10,000 hours of continuous use
(approximately one year) .
5 . Release the Cal switch and adjust the Run potentiometer until the display reads 100% .
6 . When the board is in the normal state, test the calibration by adjusting the Run potentiometer
until the display reads below 85% to determine if the low UV lamp lights, indicating the board
is functioning properly . Readjust the Run potentiometer until the display reads 100% . (The
three minute warm-up period will restart) . The UV meter board is now calibrated .
