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the SPC adjustment is made by introducing a two-part straight-line response curve with a
break point at the set point, or “standard reference.”
SPC Procedure
1.
An AutoCal must be carried out before performing an SPC.
2.
Measure the value of the reference gas with the SADPminiEx in the normal way and
note the indicated value and the stated value of the “standard reference.” [For
example, the SADPminiEx reads -70°C dewpoint, and the “standard reference gas”
is certified by the gas supplier as being -69°C dewpoint]. The instrument can now
be removed from the gas sample, to conserve the reference gas.
3.
Select ‘SPC’ from the Set-up Menu and Press the ‘ ’ key.
i.)
On the warning screen press the ‘ ’ key to continue (pressing Scroll key will
abort the procedure and go back to the Set-up Menu).
ii.)
Enter the password (if required) and press the ‘ ’ key.
iii.)
Highlight the ‘ENTER NEW SPC’ option to add a SPC to the SADPminiEx
and Press the ‘ ’ key.
iv.)
The display asks for the “SPC POINT,” enter the value measured for the
reference gas (i.e. -70°C in the above example) using the Scroll and
▲
and
▼
keys and press the ‘ ’ key.
v.)
The display asks for the “SPC VALUE,” enter the stated value for the
reference gas (i.e. the value that you want the SADPminiEx to read at this
point, -69°C in the above example) using the Scroll and
▲
and
▼
keys and
press the ‘ ’ key.
vi.)
The SADPminiEx will revert to the Set-up Menu with EXIT highlighted,
pressing the ‘ ’ key will return the instrument to the operating mode and all
readings taken will be modified in line with the offset introduced in the above
procedure.
Note- The integrity of the calibration will now be dependant on the integrity of the reference
standard against which the adjustment has been made. To restore the factory calibration,
and thus the traceability stated in the Certificate of Calibration, the SPC adjustment must
be removed.
4.
To remove a SPC from the SADPminiEx follow the above procedure to step iii.)
Then select the ‘REMOVE SPC’ option and Press the ‘ ’ key. The SADPminiEx
will revert to the Set-up Menu with the SPC removed.
11.1.6
Security
