Kahn Optidew Bench Top, User Manual

Page: 51 / 88

Optidew User’s Manual
42 October 2019
APPENDIX A
5 MAINTENANCE
5.1 Mirror Cleaning
Throughout the life of the instrument, periodic cleaning of the mirror surface and optics
window may be required. The frequency of this depends upon operating conditions and
the potential in the application for contaminants to be deposited on the mirror.
The Optidew will notify the user on the state of mirror contamination. The instrument will
initially give a warning in the sensor status display (or as a Magenta/flashing Magenta
indication on the transmitter version) when contamination is detected, but will continue
to operate. Cleaning the mirror, then running a DCC is necessary when this warning is
displayed.
If the contamination reaches levels which will drastically affect performance, a fault
alarm will trip, causing the instrument to switch to standby mode until action is taken.
For remote indication of an optics warning, the process alarm contact can be set to trip
whenever the optics warning is active. See sections 3.2 and 4.6 for further information.
Figure 31 Mirror contamination warning
The cleaning procedure is as follows:
1. Set the instrument to Standby
2. If mounted in a sample block, disconnect the sensor cable and remove
the sensor from the block.
3. Clean the mirror surface and optics window firstly with a cotton bud/Q-
Tip soaked in distilled water, then with one of the following solvents:
methanol, ethanol, or isopropyl alcohol. To avoid damage to the mirror
surface do not press too firmly on the cotton bud/Q-Tip when cleaning.
Allow the cleaning solvent to fully evaporate.
4. Press the ‘Calibrate Optics’ button in the ‘Alarms’ screen. For the Optidew
Wall Mount without display, refer to section 3.3.1.