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MAN0530 Issue 15 - 07/17
2104M0506
Receiver Gas Calibration
Methane
Ethane
Propane
Butane
Pentane
Ethylene
Propylene
Butadiene
(5)
If this is the first time that the unit has been tested with this particular test filter, record
the gas reading that is produced. This reading should be used to verify correct
operation in the future.
(6)
If this is not the first time that the unit has been tested with this particular filter, note the
gas reading and compare it to the original value recorded for this unit and filter. If the
reading is within ± 0.5 LEL.m of the original value, the unit is working correctly.
(7)
If the reading is Ok, proceed to step 13. If not Ok, the unit may need cleaning
and/or re-zeroing.
(8)
To clean the unit, first remove the test filter from the cowling.
(9)
Use a damp, lint-free, cloth or lens wipe to clean the windows of the transmitter and
`
the receiver.
Zero the unit using the SHC-1 in CALIBRATE mode.
(10)
(11)
Re-insert the test filter into the cowling in front of the receiver and verify that the
test reading is now within ± 0.5 LEL.m of the reading originally obtained with this filter.
If the gas reading is still not within the expected range, check the system alignment
(see section 3.7 Alignment and Commissioning) and repeat the test in step 6.
(12) When finished, remove the test filter and cancel INHIBIT by selecting MAIN in the menu.
(13)
Disconnect the SHC-1 Handheld Interrogator.
(14)
Store the readings in a safe place.
4.3 CALIBRATION CHECK USING THE GASSING CELL
The gassing cell is designed to allow easy calibration checking using a high concentration test
gas as opposed to the standard plastic test filters. The integrated LEL.m reading of the gas
concentration in the cell can be calculated using the following formula:
Low test Filter
Typical Response
D
0.50 – 1.1 LEL.m
C or D
0.60 – 1.3 LEL.m
B or C
0.85 – 1.1 LEL.m
B or C
0.85 – 1.1 LEL.m
B or C
0.85 – 1.1 LEL.m
B or C
0.50 – 1.3 LEL.m
B
1.00 – 2.0 LEL.m
B
1.00 – 2.0 LEL.m
Int(lel.m)
= L
xl
T
High Test Filter
F
F
F
F
F
E
E
E
*
(Conc
/ LEL
cell
gas
59
Searchline Excel
Typical Response
1.5 – 3.2 LEL.m
1.5 – 2.7 LEL.m
2.6 – 3.2 LEL.m
2.6 – 3.2 LEL.m
2.6 – 3.2 LEL.m
2.6 – 3.2 LEL.m
1.2 – 3.2 LEL.m
1.2 – 3.2 LEL.m
)
gas
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