Det-Tronics THZ HART Combustible Gas Transmitter - Manual (Page 7)

5. Be sure that the O-ring inside the sensor base is
in good condition, then re-install the cap. Tighten
only until snug. Do not over tighten.
6. Re-apply power. Allow time for the unit to warm
up and stabilize (approximately one hour for best
results), then calibrate.
An adequate supply of spare electrochemical sensor
cell assemblies should be kept on hand for field
replacement. For maximum protection against con-
tamination and deterioration, they should not be
removed from the original protective packaging until
the time of installation. To ensure maximum storage
life, electrochemical cells should be stored in the
unopened original packaging, at a temperature
between 32°F and 68°F (0 to 20°C) and a relative
humidity between 15 and 90 percent.
Hydrophobic Filter Replacement
Some electrochemical sensor housings use a
hydrophobic filter, which protects the sensor cell from
contaminants in the environment, and also enables
the operation of the cell in "wet" environments without
plugging its screen. The operator should frequently
inspect the hydrophobic filter for cleanliness. A dirty
filter can significantly reduce the amount of gas that is
able to reach the sensor cell, thereby impairing the
ability of the system to respond to a hazardous condi-
tion. If the filter becomes dirty or if it is damaged, it
must be replaced.
To replace the hydrophobic filter, simply unscrew the
existing filter from the housing, then replace it with a
new filter. Use care not to over tighten.
NOTE
A dirty hydrophobic filter can adversely affect the
response of the sensor by blocking the flow of
gas to the sensor cell. If the detector cannot be
calibrated or responds slowly to the calibration
gas, check the condition of the hydrophobic filter
before replacing the sensor cell.
REPLACEMENT PARTS
An adequate supply of spare sensors should be kept
on hand for field replacement. For maximum protec-
tion against contamination and deterioration, they
should not be removed from the original protective
packaging until the time of installation.
CAUTION
Always store and transport the sensor in the orig-
inal factory packaging to ensure proper protec-
tion against contamination.
Always calibrate after replacing either the sensor or
the transmitter circuit board.
DEVICE REPAIR AND RETURN
Prior to returning devices, contact the nearest local
Detector Electronics office so that a Service Order
number can be assigned. A written statement
describing the malfunction must accompany the
returned device to expedite finding the cause of the
failure.
Pack the unit properly. Use sufficient packing materi-
al in addition to an antistatic bag or aluminum-backed
cardboard as protection from electrostatic discharge.
Return all equipment transportation prepaid to the
factory in Minneapolis.
ORDERING INFORMATION
Sensor cells and sensor housings must be ordered
separately. When multiple gas ranges are available,
order matching sensor cells and housings.
For information regarding electrochemical gas sen-
sors, as well as sensor accessories and calibration
equipment, refer to form number 90-1079, or contact:
Detector Electronics Corporation
6901 West 110th Street
Minneapolis, Minnesota 55438 USA
Operator: (952) 941-5665 or (800) 765-FIRE
Customer Service: (952) 946-6491
Fax: (952) 829-8750
Web site: www.detronics.com
E-mail: [email protected]
7 95-8550