MultiExact Gas Analyser
5 – Installation and set-up
5.5
Setting up automatic validation/calibration (option)
5.5.1 Overview of automatic validation/calibration
Automatic validation operates in the same way as automatic calibration, except that
the transducers are not calibrated when the low and high calibration gases have been
passed through the transducers. Automatic validation therefore allows you to
determine the drift of sample measurements over time. You can set tolerance levels,
so that if the sample measurements fall outside acceptable limits, a 'maintenance
required' status is raised (
) to identify that a full calibration needs to be carried out.
If your analyser supports auto validation/calibration you have the option to:
•
Configure the analyser so that automatic validation/calibration of a transducer is
carried out once (at a preset time).
•
Configure the analyser so that automatic validation/calibration of a transducer is
carried out repeatedly at a specified frequency.
•
Use the soft keys to manually start an automatic validation/calibration
(see Section 6.2.1).
•
Use a control input signal (on the RS485, ethernet, profibus or switch input) to
initiate an automatic validation/calibration (see Section 5.2.5).
☞
You can also perform a 'remote calibration' using the switched inputs on the
calibration option pcb if they are configured accordingly (see Section 5.5.3).
☞
If your analyser is configured to provide two sample gas measurements, you
can set up and carry out two separate automatic validations/calibrations, one
for each measurement transducer.
Automatic validation/calibration provides the following functionality:
•
During an automatic validation/calibration of a transducer, the analyser controls
gas selection relays which can be used to control the flow of low and high
calibration gases into the analyser. An optional valve block can also be supplied.
•
The analyser checks that the resulting measurement is within the preset validate
target range (validate target value ± validate tolerance value).
•
If the measurement is within the preset validate target range and mode is set to
calibrate, the transducer is calibrated (as in manual calibration).
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