Hach Orbisphere 51 Series User Manual Download

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Calibration menu

8.1

K1200 sensor calibration

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 (refer to

Calibration configuration on page 60

for more details), but these parameters can

be changed.
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, 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.

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.
Select the

Configuration

option from the

Gas sensor

calibration menu to check the calibration

parameters.
Ensure the parameters are set up as illustrated left:

•

Auto-calibration

: This option is not available for the K1200 sensor.

•

Manual-calibration Auto-End

: On by default.

•

Hold during calibration or verification

: On by default.

•

Zero calibration bottle

: Ensure this is

disabled

by unchecking the box as it is not relevant for the

K1200 sensor.

Exit from the configuration screen by pressing on

. Then select

Calibration

from the

Gas sensor

calibration menu and perform a manual zero calibration as described in

Zero calibration on page 61

. For

high range sensors perform an additional 100% humid air calibration as described in

100% humid air

calibration (high range sensors only) on page 61

Manual calibration

Manual calibrations can be made at any time. Perform a calibration by following these steps:

Remove the sensor from the sample line.

Rinse the sensor head with clean water.

Wipe the sensor head with a clean soft tissue to remove any excess moisture.

If using the supplied calibration device (refer to

Portable calibration device - K1200 sensor on

page 38

), 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.

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 0.1 L/min. If
you are

not

using the supplied calibration device with pressure reducer, the

maximum

allowable

inlet pressure must be no more than 2 bar absolute.

Configure the calibration as described in

Calibration configuration on page 60

Start the calibration as described in

Zero calibration on page 61

100% humid air calibration (high

range sensors only) on page 61

depending on the preferred calibration method.