WIKA GIR-10 Mode D'emploi page 22

7. Maintenance, cleaning and recalibration
Following the calibration of the instrument with a certified test gas, the accuracy
of the gas presence detector at this SF₆ gas concentration is increased. When
changing the programmable points of the calibration (outside the factory
calibration), the accuracy for other concentrations can deviate from the specified
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tolerances. The operator who performs the span calibration must be aware of
this analytical dependency.
Performing a recalibration
1. Keep the " Power " and " Select " buttons on the underside of the console case
pressed.
⇒
Instrument starts and opens the settings mode.
⇒
Message "SETUP" shows on the display of the console.
⇒
The first menu item (serial number) is shown on the display of the console.
2. Leave the instrument switched on for at least 10 minutes in order to reach the
optimal internal temperature stability.
3. Connect the gas presence detector to a pressure-free vessel with a certified test
gas mixture of SF₆ gas in synthetic air.
Ensure that no overpressure exists at the sensor.
4. Open the valve of the vessel immediately and wait until the reading on the displays
has stabilised. Keep the vessel connected to the instrument.
5. Press the "Select" button until "Calibr.:" is shown on the display of the console.
6. Press the "+" button.
⇒
The console display shows the current measured value.
⇒
The current measured value remains displayed.
7. Press the "+" or "-" button to set the set point.
⇒
The set point is shown on the display of the hand-held.
8. Complete the calibration by confirming the "Select" button.
⇒
On changing the menu point, the value is automatically saved.
⇒
The calibration is active.
A recalibration by the operator can be reset or deleted (→ see chapter 5.5
"Settings"). The recalibration by the manufacturer remains untouched by a
recalibration by the operator. Without a saved recalibration by the operator,
the factory calibration remains active.
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The set point is specified on the certificate of the test mixture.
The set point can be changed by up to ±1/3 of the measured value. The
minimum and maximum values are 2 ppm
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WIKA operating instructions gas detector, model GIR-10
nd 50 ppm .
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