Servomex DF-130E, Operator'S Manual

Page: 52 / 88

48 DF-150E Maintenance and Calibration Checks
10.2Calibration
All Servomex analyzers are calibrated with certified gas standards at the
factory prior to shipment. No additional calibration is required before use.
Depending on the application, the span calibration should be checked
approximately every twelve months using a gas of known concentration and
high quality plumbing components. For applications with background gases
containing aldehydes, alcohols or acids the span calibration should be checked
every three months and electrolyte changes may be necessary. Contact
Servomex for specific maintenance recommendations.
NOTE
Unless otherwise requested, the analyzer is factory calibrated on
nitrogen. Analyzer readings will be inaccurate if used with a
background gas other than the one for which it is calibrated. If the
analyzer was calibrated on a gas other than nitrogen, the gas will
be noted on the calibration log inside the front door and on a label
below the display. See the section on Gas Scale Factor on page 25.
10.2.1 Adjusting Calibration
If an adjustment to the calibration is required, the following procedures should
be completed.
10.2.1.1 A. Log the present calibration reference values
NOTE: The factory calibration reference values are recorded on the sensor.
1. Open the front door.
2. Locate the View Ref. toggle switch. See Figure 28
3. Throw the toggle switch to Span, and record the Span Calibration
Reference Value as shown on the display. The number will be preceded by
a negative sign to differentiate it from an oxygen reading. Ignore the
decimal point as it will be in a different position depending on the selected
range.
4. Similarly record the Zero Calibration Reference Value.
5. Release the toggle switch.
6. Allow 10 seconds for the analyzer to return to normal operation.