Automatic Shutdown; Measurement Mode; Sensor Calibration - Hach ORBISPHERE 3654 Manuel D'utilisation De Base

6.4.8 Automatic shutdown

Choose Automatic Shutdown Status from the Configuration menu to activate the Automatic
Shutdown feature.
If you select Enable, the instrument switches off automatically after 10 minutes of inactivity, thereby
economizing battery power.

6.4.9 Measurement mode

Choose Measurement Mode from the Configuration menu to enable maximum measurement
mode for sampling in bottles and cans.
In Maximum measurement mode, the instrument searches for two consecutive measurements with
less than a 2% difference, as also described in
the display is frozen and you may store the data. The instrument remains in this mode until you
select Normal measurement mode.
Section 7 Calibration
7.1 Barometric pressure sensor calibration
You must have access to an accurate barometer to calibrate the instrument's internal barometric
pressure sensor. This is done using the Hach 3654 program on the PC. Choose Troubleshooting,
Pressure Calibration and a message will warn you that the current calibration will be lost.
Choose OK to continue. The calibration procedure then displays a Pressure Calibration dialog box.
The Measured Pressure value shows the current instrument pressure reading.
Enter the current atmospheric pressure, in mbars, in the Calibration Pressure entry box. Choose
Calibrate to direct the instrument to read and display the Measured Pressure using this calibration
value. Choose Quit when you are satisfied with the pressure calibration to return to normal
operation.

7.2 Sensor calibration

The TC sensor can be calibrated in pure H
following table gives information regarding the different methods.
Calibration Method
Gas at atmospheric
pressure
Gas at elevated
pressure (2-3 bar)
Before calibrating check that the sensor membrane surface is tight, smooth and wrinkle free. Select
the gas measurement phase for calibration. Refer to
select the calibration medium using the Hach 3654 program. Refer to
on page 20.
Ensure that normal measurement mode is selected in the Measurement Mode menu of the Hach
3654 program. Refer to
Calibration must only be carried out once the TC sensor is giving a stable measurement. Expose the
membrane to the calibration sample until this stable reading is obtained. This usually takes about
5 minutes.
For calibration it is important that the sensor's membrane is at the same temperature as the
calibration sample. Therefore, allow some sample to pass through the flow chamber for 3 minutes
before calibrating.
or N
2
Table 3 Sensor calibration information
Time Benefits
5 min Quick and easy
10 min Higher accuracy than
atmospheric method.
Validation of the
sensor linearity
Measurement mode on page 21.
Measurement mode on page 14. When this occurs,
gas at atmospheric or elevated pressure. The
2
Drawbacks
Less accurate than
other methods
Requires a certified
pressure gauge
Gas measurement phase
Reference
Gas with known
purity, certified
barometer
Certified pressure
gauge
on page 19. Next,
Calibration medium
English 21