Maintenance Schedule; Clean The Sensor - Hach 8350.3 Benutzerhandbuch

Chemical exposure hazard. Obey laboratory safety procedures and wear all of the personal protective
equipment appropriate to the chemicals that are handled. Refer to the current safety data sheets
(MSDS/SDS) for safety protocols.
Chemical exposure hazard. Dispose of chemicals and wastes in accordance with local, regional and
national regulations.

5.1 Maintenance schedule

Table 1 shows minimum times for regular maintenance tasks. Perform maintenance tasks more
frequently for applications that cause electrode fouling.
Task

Clean the sensor

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Examine the sensor for damage
Calibrate the sensor
5.2 Clean the sensor
Pre-requisite: Prepare a mild soap solution with a non-abrasive dishwashing detergent that does not
contain lanolin. Lanolin leaves a film on the electrode surface that can degrade the sensor
performance.
Examine the sensor periodically for debris and deposits. Clean the sensor when there is a buildup of
deposits or when performance has degraded.
1. Use a clean, soft cloth to remove loose debris from the end of the sensor. Rinse the sensor with
clean, warm water.
2. Soak the sensor for 2 to 3 minutes in the soap solution.
3. Use a soft bristle brush to scrub the entire measuring end of the sensor.
4. If debris remains, soak the measuring end of the sensor in a dilute acid solution such as < 5%
HCl for a maximum of 5 minutes.
5. Rinse the sensor with water and then return to the soap solution for 2 to 3 minutes.
6. Rinse the sensor with clean water.
Note: Sensors with antimony electrodes for HF applications may require additional cleaning. Contact technical
support.
Always calibrate the sensor after maintenance procedures are done.
5.3 Prepare for storage
For short-term storage (when the sensor is out of the process for more than one hour), fill the
protective cap with pH 4 buffer (recommended) or tap water and put the cap back on the sensor.
Keep the process electrode moist to avoid slow response when the sensor is returned to operation.
For extended storage, repeat the short-term storage procedure every 2 to 4 weeks, depending on the
environmental conditions. Refer to for temperature storage limits.
W A R N I N G
C A U T I O N
Table 1 Maintenance schedule
90 days
X
X
Set by regulatory agencies or experience
1 year
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