Advertisement
Calibration
Manual Calibration
Calibration
4-22
42iQTL Instruction Manual
Note however, that the EPA requires a minimum of one multipoint
calibration per calendar quarter. Such a quality control program is essential
to ascertain the accuracy and reliability of the air quality data collected and
to alert the user if the accuracy or reliability of the data should become
unacceptable. A compilation of this kind might include items such as dates
of calibration, atmospheric conditions, calibration factors, and other
pertinent data.
Use the following procedure to perform a zero and span check.
1. Connect the zero gas to the SAMPLE bulkhead in a standard
instrument or to the ZERO IN bulkhead in a 42iQTL equipped with
the zero/span and sample solenoid valve option.
2. Allow the instrument to sample zero gas until a stable reading is
obtained on the NO, NO
readings. Unless the zero has changed by more than ±0.010 ppm, it is
recommended that the zero not be adjusted. If an adjustment larger
than this is indicated due to a change in zero reading, a new multipoint
calibration curve should be generated.
3. Attach a supply of known concentration of NO and NO
generated via an NIST traceable NO working standard and a GPT
system) to the SAMPLE bulkhead (or SPAN bulkhead for instruments
equipped with the zero/span and sample solenoid valve option) on the
rear panel.
4. Allow the instrument to sample the calibration gas until a stable
reading is obtained on the NO, NO
calibration has changed by more than
calibration curve should be generated.
5. When the calibration check has been completed, record the NO, NO
and NO
6. Reconnect the analyzer sample line to the SAMPLE bulkhead.
Manual
The Manual Calibration screen allows the user to view and manually adjust
the zero background and span coefficient. These are used to correct the
NO, NO
internal calibration data.
, and NO
2
values.
x
, and NO
readings that the instrument generates using its own
2
x
channels then record the zero
x
(usually
2
, and NO
channels. If the
2
x
10%, a new multipoint
,
2
Thermo Scientific
Advertisement
Chapters
