Honeywell 3000 MKII Series Technical Manual page 22

SERIES 3000 MKII TECHNICAL MANUAL S3KMKIIMAN MAN0878 issue 13 04/23
To maximize the accuracy of the calibration, please follow the special process for calibration of EtO
cartridges as follow:
Transportation and Installation
Note: Ethylene oxide sensors are supplied on a transportation board in order to keep the cell biased at
the correct level. Once removed from the transportation board the sensor should be fitted to the detector
as soon as possible.
If the sensor is not fitted to the transportation board or a powered detector, its bias will decay and the
sensor will take up to 24 hours to recover. During this period the sensor will not function as a gas detector,
reporting a gas reading above full scale.
When calibrating ethylene oxide sensors, the following should be taken into account:
1. Use the official calibration adaptor (S3KCAL) when applying cylinder gas to the sensor.
2. PTFE tubing should be used to minimise the effects of coating and gas absorption during the procedure.
3. Tubing lengths should be kept as short as possible.
4. Calibration gas should be flowed for a minimum of 5 minutes through the system before performing
a span calibration.
5. A flow 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) humidified 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 confirm 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 five minutes before commencing the span calibration in accordance
with the detector's instructions to confirm the span calibration.
5. After the span calibration, the sensor should be allowed to recover in clean ambient air, or clean
air humidified to approximately ambient humidity levels for fifteen minutes and then should be zero
calibrated under these conditions. Note that this does not affect the span sensitivity of the instrument.
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