Det-Tronics U9500 Infiniti Gas Transmitter - Manual (Page 33)

95-8444 31 10.1
Contaminating Gases And Vapors for Catalytic
Sensors
Gases and/or vapors that can cause permanent loss of
sensor sensitivity:
– Silicone compounds often found in oils, greases
and resins.
– Antiknock compounds such as tetra ethyl lead,
tetra methyl lead and phosphate esters.
Gases and/or vapors that can cause inhibition (temporary
loss of sensitivity) of the sensing element:
– Volatile halogenated compounds.
– Tetrachloroethylene.
– Fluorinated hydrocarbon.
– Vapors that result from hot P.V.C.
– Acids and various solvents may cause a shift in the
zero of electrochemical sensor.
– Chlorine and Chlorinated HC.
NOTE
The sensor must be periodically inspected and
calibrated following prolonged exposure to
contaminating gases and vapors.
mAINTENANCE
CaUTiOn
Be sure to secure all output devices that are
actuated by the system to prevent unwanted
activation of this equipment, and remember to
place these same output devices back into service
when the checkout is complete.
• Periodically apply a generous amount of Lubriplate
grease (part number 102868-001) to the internal
threads on the junction box cover using an
application tool. DO NOT use other lubricants, since
some materials can cause irreversible damage to the
sensing element in the gas sensor.
• To ensure reliable protection, it is important to check
and calibrate the detection system on a regularly
scheduled basis. The frequency of these checks
is determined by the requirements of the particular
installation - 90 days is typical.
• Fault detection circuitry continuously monitors for
problems that could prevent proper system response.
It does not monitor external response equipment or
the wiring to these devices. It is important that these
devices be checked initially when the system is
installed, as well as periodically during the ongoing
maintenance program.
• The system must be checked periodically in the
Normal mode to ensure that those items not checked
by the transmitter diagnostic circuitry (such as output
relays) are functioning properly.
SENSOR AND HYDROPHOBIC FILTER
REPLACEMENT
CaUTiOn
Be sure to secure all output devices that are
actuated by the system to prevent unwanted
activation of this equipment, and remember to
place these same output devices back into service
when the checkout is complete.
Catalytic Sensor Replacement
For catalytic combustible gas sensors, it is necessary to
replace the entire sensor assembly when it is defective.
Follow the procedure below to replace the sensor.
1. Remove power to the transmitter prior to replacing
the sensor.
2. Remove the transmitter cover and the wire shield
within the transmitter. If a sensor termination box
was used, remove the sensor junction box cover.
3. Unplug the sensor from the transmitter module (if a
sensor termination box was used, unplug it from the
plug inside the termination box) and unscrew it from
the conduit entry.
4. Thread the wires for the replacement sensor through
the conduit entry, then screw the sensor into the
conduit entry and plug it in. Replace the wire
shield.
5. Replace the junction box cover.
6. Re-apply power. Allow time for the unit to warm
up and stabilize (approximately 24 hours for best
results), then calibrate.