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

In the case of a calibration failure, attempt a second calibration after about 5 minutes. If the second
attempt also fails, then refer to your Hach representative for advice.
Note: If the Auto-End parameter is enabled then the calibration will be considered successful when the parameters
defined in Stop parameters are met.
If you have not accepted or cancelled the calibration after an elapsed time of 10 minutes then the
process will time-out.
7.4.1.4.3 100% humid air calibration (high range sensors only)
With this method, the sensor should be removed from the sample and exposed to air saturated with
humidity. Do this by putting a drop of water in the calibration cap before installing the cap on the
sensor. Press Start to start the calibration. The process is then the same as for the Zero calibration
described previously.
7.4.1.4.4 High level adjustment
Note: Before using this option, ensure a zero calibration has been successfully completed first.
This calibration exposes the sensor to a gas or a liquid sample with a known gas concentration. You
also have the option to reset the sensor's calibration parameters to factory settings (from drop-down
list for Cal. sample).
Press Start to start the calibration. The process is then the same as for the Zero calibration
described previously.
7.4.2 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
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) in the sample, the sensor lifetime can also be shorter.
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