Hach ORBISPHERE 51 Serie Allgemeines Benutzerhandbuch Seite 22

7.4 Calibration
Calibrations can only be performed once the instrument has been installed and configured.
Note: The temperature sensor is factory calibrated and can only be changed by a Hach representative.
7.4.1 K1200 sensor calibration
7.4.1.1 Sensor calibration
The sensor can be calibrated manually on an ad hoc basis. By default, the mode is set to zero
calibration with auto-end.
For higher level concentrations (above 1% oxygen which corresponds to about 400 ppb dissolved
O ) a high level adjustment can be performed using a gas mixture containing more than 1% oxygen,
2
or a known line sample. However, this should not be done without first ensuring the zero point is
accurate. This can be achieved by performing a zero calibration first.
Low range sensors: (K1200-L spots)
There are two calibration modes available - zero or high level adjustment. The sensor is factory
calibrated at zero. During use, the zero calibration is the best calibration to guarantee the sensor
specifications. After a spot replacement, a zero calibration is recommended.
High range sensors: (K1200-H spots)
There are three calibration modes available - zero, high level adjustment or in 100% humid air. The
sensor is factory calibrated at zero and in 100% humid air. During use, humid air calibration is the
best calibration to guarantee the sensor specifications. After a spot replacement, a zero calibration
and a 100% humid air calibration are recommended.
7.4.1.2 Initial sensor calibration
The sensor has been calibrated at the factory prior to shipment and is ready for use upon delivery.
However, if the sensor has not been used for a period of more than six months since delivery or if the
sensor spot has been replaced or changed in any way, then a sensor calibration will be required.
1. From the Main menu, select Calibration followed by Gas sensor and then Configuration. Make
sure the parameters are set as follows:
Option
Auto-calibration
Manual-calibration
Hold during calibration or
verification
Zero calibration bottle
2. Exit from the configuration screen by pressing OK.
3. Select Calibration and perform a manual zero calibration as described in
on page 24. For high range sensors perform an additional 100% humid air calibration as
described in 100% humid air calibration (high range sensors only)
7.4.1.3 Manual calibration
Manual calibrations can be made at any time by following these steps:
1. Remove the sensor from the sample line.
2. Rinse the sensor head with clean water.
3. Wipe the sensor head with a clean soft tissue to remove any excess moisture.
4. If using the supplied calibration device insert the sensor into the sensor holder on top of the
calibration device. If not using the calibration device insert the sensor into the flow chamber.
5. Flow the calibration sample through the calibration device or flow chamber as applicable. If using
the calibration device fully open the valve on the pressure reducer to give a gas flow rate of
22 English
Description
Not available for this sensor.
Make sure that the Auto-End box is checked.
Make sure this box is checked.
Make sure this is disabled by unchecking the box as it is not relevant for
this sensor.
Zero calibration
on page 24.