XNX Universal Transmitter
Section 3 - Calibration
107
5. A ow rate of 300 to 375 ml/min should be maintained throughout
the calibration procedure.
Zero Only Calibration
If the sensor is to be zero calibrated only (no span calibration), the
calibration should be performed in clean ambient air or clean air (not
nitrogen) humidied to approximately ambient humidity levels.
Full Calibration
If performing a full calibration (zero and span) the following procedure
should be used:
1. Apply clean, dry air (not nitrogen) to the sensor for 5 minutes. Do not
use background air.
2. Zero the sensor in accordance with the detector’s instructions to
conrm the zero calibration.
3. Apply the span calibration gas to the sensor immediately after the
zeroing procedure. Do not allow the sensor to return to ambient air
conditions between steps 2 and 3.
4. Apply the span gas to the sensor for ve minutes before
commencing the span calibration in accordance with the detector’s
instructions to conrm the span calibration.
5. After the span calibration, the sensor should be allowed to recover
in clean ambient air, or clean air humidied to approximately ambient
humidity levels for fteen minutes and then should be zero calibrated
under these conditions. Note that this does not affect the span
sensitivity of the instrument.
Ozone
The calibration is performed using 0.2 ppm ozone (O
3
). Honeywell
Analytics strongly recommends that a suitable O
3
generator be used
for this operation such as the ACD Genie O
3
. This device generates
ozone at the target concentration of 0.2 ppm and maintains a regular
ow rate throughout the calibration. During the calibration, please pay
attention to the following points:
1. PTFE tubing should be used to minimise the effects of coating and
gas absorption during the procedure.
2. Tubing lengths should be kept as short as possible.
3. The ow rate of the ADC Genie O
3
generator depends on
the concentration set and cannot be adjusted by the user. At a
concentration of 0.2 ppm, the ow rate will be 1 lpm.
4. Calibration gas should be owed for a minimum of 5 minutes
through the system before performing a span calibration.
5. Refer to the manufacturer’s operating instructions supplied for full
details on the operation of the O
3
generator.
705/705HT Calibration
For complete calibration and conguration information, see the
Type
705 Operating Instructions
(Honeywell part number 00705M5002).
Sensepoint/Sensepoint HT Calibration
For complete calibration and conguration information, see the
Sieger
Sensepoint Technical Handbook
(Honeywell part number 2106M0502).
Searchpoint Optima Plus Calibration
Complete calibration and conguration information can be found
in the Searchpoint Optima Plus Operating Instructions (Honeywell
part number 2108M0905). If properly installed and maintained, the
Searchpoint Optima Plus sensor will not require routine calibration.
This is due to the inherent stability of the IR absorption process and
the unit’s fully compensated optical conguration.