Ion Science TVOC - Manual (Page 20)

TVOC MANUAL Ion Science Ltd
Page 20 of 32
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2 The SPAN LED will stop flashing after approximately 2 minutes.
3 Turn off the gas and disconnect the equipment
Calibration
NB during the span measurement process the mV reading of the span must be greater than the zero level to
pass the ZERO calibration stage.
An acceptable SPAN calibration level will result in the illumination of the green STATUS LED.
An unacceptable SPAN calibration level will result in the illumination of the red FAULT LED. Should this
occur the previous calibration levels will be used when the instrument returns to normal operation. The
Yellow span LED will be illuminated to indicate the failure to calibrate the span.
Now place the magnet over the logo corner to return to normal monitoring routine.
The GREEN LED will start flashing as TVOC starts its cycle with a lamp ON cycle.
If either the ZERO and/or SPAN levels were outside acceptable levels the RED LED will flash until an
acceptable calibration has been carried out.
Unacceptable calibration levels will not be adopted; the instrument will default to the previously stored
acceptable calibration factor.
NOTE:
*
Always check the accuracy of your calibration by checking readings from TVOC when it is running
normally using the ZERO filter and SPAN gas.
* Accuracy of calibration is the responsibility of the person carrying out the calibration. If in doubt seek
advice.
* TVOC must be calibrated after lamp/cell cleaning or general maintenance.
NOTE: Causes of contamination and error in signal:
*
Changes in air pressure when detecting ppm concentration
* Variation in oxygen, argon beyond ambient levels.
* Variation in ambient moisture content.