Other Menus; Sensor Maintenance - Hach ORBISPHERE 51 Série Manuel D'utilisation Simplifié

• The value "% ideal current" is a percentage of the current against the ideal current for the
membrane type selected. If this percentage is not within the accepted range, an error message
is displayed and the calibration process fails. A warning message can be displayed when this
value is close to the boundaries, but when calibration can be accepted.
• The message is first displayed in the result box. The dialog box with the error message or the
warning is displayed when the finish button is pressed.
• The value "% last calibration" shows the ratio between the current measurement and the
previous sensor calibration.
• The value "% variation" indicates the variation during the last 3 measurements, which is the
stability of the measurements. A variation as low as possible is needed for a precise
calibration.
• The display shows the actual calibration parameters, and the actual readings (temperature,
barometer, current).
7.4.3 Barometric pressure calibration
Note: The barometric pressure sensor has been factory calibrated but should be periodically verified with a
precision certified barometer. This is only necessary if measuring in gas phase with fraction units (%, ppm).
The upper box shows the barometric pressure as measured by the instrument.
Using a precision certified barometer measure barometric pressure in the location where the
measuring instrument is used. Compare the values and if they are the same press Cancel, otherwise
enter the new barometric pressure value in the lower box and press Validation to validate the new
setting.

7.5 Other menus

For information on setting up relays and analog outputs refer to the full user manual (Inputs/Outputs
menu).
For information on setting up RS485, PROFIBUS-DP, USB, HTTP/TCP-IP and attached PRINTER
links refer to the full user manual (Communications menu).
For information on setting up products and global configurations refer to the full user manual
(Products and Global Configuration menus).
Section 8 Maintenance
8.1 Instrument maintenance
Personal Injury Hazard. Any instrument maintenance should be carried out by a qualified Hach Service
Technician. Please contact your local representative should you feel any maintenance or instrument adjustments
are required.

8.2 Sensor maintenance

The sensor spot needs to be replaced about once a year. The procedure is very simple and takes no
more than a couple of minutes. Based on the measurement range of oxygen, the sensor lifetime can
be shorter and the maintenance—and calibration—frequency increased. If there are bleaching
compounds and strong oxidants (e.g., ClO
C A U T I O N
) in the sample, the sensor lifetime can also be shorter.
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