Detcon PI-700 - Manual (Page 34)

Model PI-700
PI-700 Instruction Manual Rev. 2.5 Page 30 of 54
filter may vary depending on the application; however, it is advised to change it out at least on a 18-24 month
cycle.
In addition, a small moisture control packet (P/N 960-700PID-000) Figure 15 is banded around the plug-in
PID sensor. This helps the sensor maintain better zero stability in extremely high humidity conditions. It is
only to be used in conjunction with the secondary filter discussed previously. This moisture control packet
should be replaced on an 18-24 month cycle.
Figure 14 Splashguard Adapter with Integral Filter
Figure 15 Plug-in sensor with Moisture control packet
It is also possible, under certain ambient contamination conditions, that the sensor’s Detector Cell may have a
partially conductive film that forms across the contact grids. This condition causes the zero background signal
to gradually increase to the point where it becomes unacceptable for the range of signal input to the transmitter
electronics. When this occurs the detector cell should be replaced. This can be checked by examining the
amount of raw signal that is produced during exposure to zero gas. Refer to the ‘View Program Status’ menu
and record the Raw Signal report after 5 minutes of zero gas exposure. A value that exceeds 3000 counts
would be evidence of this problem.
General recommendations for Sensor Maintenance
 For normal environmental exposure and signal decay, replace the plug-in sensor every 9-12 months.
(especially if there are no skilled technicians to handle proper UV lamp replacement.)
 If skilled technicians are available, replace just the UV lamp every 9-12 months.
 For abnormally high rates of signal decay, clean the UV lamp monthly, using a Lamp Cleaning Kit, and
replace the UV lamp every 9-12 months.
 For any proven cases where the zero baseline has drifted up, replace the detector cell.
Detcon P/N 960-700PID-000
Avoid contact with crystals