Point Calibration; Figure 26 1 Point Calibration Page - Michell Instruments XTP601 User Manual

XTP601 User's Manual
3.1

1 Point Calibration

This is a single point offset overlaid on top of the factory calibration. It is designed to
correct minor drift and minor changes during transit. This calibration makes the unit
very accurate at the calibration point and improves accuracy throughout the range.
The calibration gas should be of a value that is within the main area of interest, i.e.
if main points of interest for a 0-25% range instrument are around the 6% area then
apply a calibration gas as close as possible, in the example below we used 6.5% O2.
1. Apply the calibration gas and purge the unit for at least 5 minutes.
View the chart until a flat line shows for 1-2 minutes.
21
%
6
t-2
2. Press
ENTER
the Field Cal page using the
CAL TYPE and set to 1 POINT. Press
3. Press
ENTER
) buttons to match the value of the concentration of the calibration
(
gas. NOTE: This value only needs to be set when using a new
gas cylinder. Press
4. Ensure the Adjusted value at the bottom of the page has stabilized
NOTE: There will be a ~ symbol next to 'Adjusted' while the
reading is stabilizing. When the ~ symbol disappears the
reading will be stable and the next change can be made.
5. Press
ENTER
3 times. Ensure that the Adjusted value equals the REF Gas 1 value
(±0.01%). Press
Menu.
6. The Adjusted reading will now be the same as that displayed on the
Main Page and be equal to the calibration gas.
7. The calibration process is complete. Return to sampling the process
gas.
NOTE: On entering the field calibration page (whether or not a change has
been made), the Pressure Compensation is switched off. After calibration go
to the Settings Page (see Section 2.7.1) and re-set any feature that may have
been turned off during the calibration process.
Michell Instruments
t
Figure 25 1 Point Calibration Page
to open the Passcode Page - 1919 Passcode. Navigate to
() button. Press
Up
to highlight REF GAS 1 and use the
to de-select.
ENTER
to highlight ACTUAL 1 value and press the
to de-select. Press
ENTER
7
%
6
t-2
ENTER
to de-select.
ENTER
() and
Up
Up
to return to the Main
ESC
CALIBRATION
t
to highlight
Down
() button
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