Det-Tronics THZ HART Combustible Gas Transmitter - Manual (Page 6)

MAINTENANCE
ROUTINE MAINTENANCE
The DEC-THZ requires no routine maintenance,
except for periodic checks to ensure proper calibra-
tion. The frequency of these checks is determined by
the requirements of the particular installation.
Calibration gas kits are required for these checks.
CAUTION
Be sure to secure all output devices that are
actuated by the system to prevent unwanted acti-
vation of this equipment, and remember to place
these same output devices back into service
when the checkout is complete.
SENSOR / HYDROPHOBIC FILTER REPLACE-
MENT
Electrochemical Sensor Cell Replacement
Follow the procedure below to replace the sensor
cell.
1. Remove power to the transmitter prior to replac-
ing the sensor cell.
2. Remove the cap from the sensor base. See
Figure 4. (There is no need to remove the sensor
base from the junction box for this operation.)
NOTE
Compare part numbers to be sure that the correct
replacement cell is being used.
3. Remove the old sensor cell. The sensor cell con-
tains a small amount of lead – dispose of proper-
ly. Check for corrosion or contamination on the
terminals of the sensor base, and clean if neces-
sary.
4. Determine proper orientation for the new cell, then
carefully plug it in.
NOTE
Handle the sensor cell carefully. To avoid possible
damage, observe the normally accepted proce-
dures for handling electrostatic sensitive devices.
See form 75-1005 for additional information.
6
C1203
SENSOR BASE
SENSOR CELL
CAP
HYDROPHOBIC FILTER
Figure 4—Electrochemical Sensor Parts Identification