Model TP-524D
TP-524D Instruction Manual
Rev. 0.8
Page 26 of 37
4.
Service and Maintenance
Calibration Frequency
In most applications, monthly to quarterly span calibration intervals will assure reliable detection. However,
industrial environments differ. Upon initial installation and commissioning, close frequency tests should be
performed, weekly to monthly. Test results should be recorded and reviewed to determine a suitable
calibration interval. If, after 180 days, an AutoSpan Calibration is not performed, the sensor will generate an
AutoSpan Fault.
Calibration/Bump Test Following Ingress Protection Events
Although the Model TP-524D/624D detector models are designed for IP 66 Ingress Protection, it is a
mandatory requirement from the ISA 92.00.01-2010 Performance Standard that this device requires that a gas
bump test or span calibration is performed shortly after any event where the conditions of IP66 ingress have
been presented to the detector. An example would be after an extreme wash-down event, or after sustained
and concentrated dust exposure event. In these cases, the unit must be confirmed to be reading accurately
before safe operation is restored.
NOTE
: It is mandatory to bump test or span calibrate the detector following field situations
where exposures to IP 66 level ingresses from dust or water have been presented.
Visual Inspection
The Sensor should be inspected annually. Inspect for signs of corrosion, pitting, and water damage. During
visual inspection, the Splash Guard should be inspected to insure that it is not blocked. Examine the porous
316SS flame arrestor within the sensor’s bottom housing for signs of physical blockage or severe corrosion.
Also, inspect inside the Junction Box for signs of water accumulation or Terminal Block corrosion.
Condensation Prevention Packet
A moisture condensation packet should be installed in every explosion proof Junction Box. The moisture
condensation prevention packet will prevent the internal volume of the J-Box from condensing and
accumulating moisture due to day-night humidity changes. This packet provides a critical function and should
be replaced annually. Detcon’s PN is 960-202200-000.
NOTE:
A desiccant cap with a desiccant packet is attached to the sensor cell housing to avoid
damage during storage and shipping. This prevents water from contacting the sensor film, and
as a result helps to retain the stability of the factory span calibration.
NOTE
: Store the desiccant caps with the desiccant packets in a sealed container (i.e. zip-lock
bag) for future use. It is advisable (but not mandatory) to reinstall the desiccant cap and packet
during prolonged periods without power (more than 1 day is considered “prolonged”). An
active desiccant packet is blue in color and turns pink when consumed. (P/N 960-399800-000
Package of 10)
Replacement of H
2
S Sensor
NOTE
: It is necessary to remove power while changing the H
2
S sensor in order to maintain
area classification while the junction box cover is removed. Proper “Hot Permits” may apply.
