Calibration; General; Calibration Check; Calibration Adjustment - GE Druck DPI 610 User Manual

Calibration

General

The instrument is supplied by the manufacturer, complete with calibration certificate(s). A
calibration period of 12 months is recommended. The actual calibration interval
depends on instrument usage and the total measurement uncertainty acceptable for the
specified application.
The DPI 610 IS and DPI 615 IS are very precise measuring instruments and the test
equipment and conditions of test must be suitable for the type of work. A Class A
compensated deadweight tester must be used. The calibration check and calibration
adjustment should be carried out in a controlled environment by a calibration
technician*.
The manufacturer offers a comprehensive and, if required, UKAS accredited calibration
service.
* A calibration technician must have the necessary technical knowledge,
documentation, special test equipment and tools to carry out the calibration work
on this equipment.

Calibration Check

At the chosen calibration interval, the instrument readings should be compared with a
known pressure standard.
The recommended method starts at 0, increasing in 20% steps to 100% full-scale and
then decreasing in 20% steps to 0.
Note any deviations between the instrument and the pressure standard and consider
traceability (accuracy to a National Standard).
If, after a calibration check, the results exceed the tolerance in the specification (or other
suitable performance standard), carry out a calibration adjustment.

Calibration Adjustment

If the instrument is operating correctly, only zero and full-scale calibration will vary. Any
excessive non-linearity or temperature effects indicate a fault. The instrument should be
returned to a qualified service agent.

Guide to Calibration Procedures

• Use high quality Repeatable and Linear pressure sources and allow adequate
thermal stabilization time before calibration (minimum 1 hour).
• Conduct the calibration in a temperature controlled and preferably, humidity
controlled environment. Recommended temperature is 21°C, ±2°C (70°F, ±4°F).
• Use deadweight testers carefully and away from draughts.
• Review and become familiar with the whole calibration procedure before
commencing the calibration process.
• The calibration routines cannot be accessed when the instrument is in BASIC mode.
Use the TASK key to select another mode (e.g.) ADVANCED before accessing the
CALIBRATION mode.
41 K0430 Issue No. 2