KROHNE OPTISENS ORP 8590 EN - Manual (Page 23)

SERVICE
5
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OPTISENS ORP 8590
www.krohne.com 01/2014 - 4001933801 MA OPTISENS ORP 8590 R01 en
Service
5.1 Maintenance
5.1.1 Cleaning
• Clean the platinum sensor surface with demineralised water.
• Slight dirt residues or dust: Rinse the sensor tip with demineralised water and clean it with a
soft tissue.
• Oily and greasy coatings: Remove with a warm soap solution and rinse with demineralised
water.
• Hardness deposits or metal hydroxide deposits: Soak the sensor tip including diaphragm in
10% citric acid or hypochloric acid for a couple of minutes and rinse the complete glass shaft
of the sensor with demineralised water.
• Biological fouling: Soak the sensor tip including diaphragm in 10 % pepsin solution for
minimum 3 hours and afterwards rinse the complete glass shaft of sensor with demineralised
water.
5.1.2 Aging and re-calibration
During operation, but already during storage, ORP sensors age due to poisoning effects of the
inner buffer system. Therefore it is important to re-calibrate the sensors in regular intervals as
described on page 18.
When the sensor becomes too old to provide reliable measurements, the signal converter
displays an error message after the calibration procedure. In this case, the sensor has to be
exchanged.
Aging effects ORP sensors:
• Shift of zero point: Shift of zero point: Shift of zero point: Shift of zero point: Compare the value with the sensor specified "Offset"-Value printed on the
"user manual sensors" (scope of delivery). The zero point of the sensor should be near +/- 5
mV compared to "offset" value. In this case perform a one-point calibration. For more
information refer to
Calibration on page 18. Compare the calibration value with the reference
value. If the calibration value deviate more than +/- 5 mV from the reference value, the sensor
should be replaced by a new one.
5.2 Spare parts availability
The manufacturer adheres to the basic principle that functionally adequate spare parts for each
device or each important accessory part will be kept available for a period of 3 years after
delivery of the last production run for the device.
This regulation only applies to spare parts which are subject to wear and tear under normal
operating conditions.
5.3 Availability of services
The manufacturer offers a range of services to support the customer after expiration of the
warranty. These include repair, maintenance, technical support and training.
INFORMATION!
For more precise information, please contact your local sales office.
.book Page 23 Friday, January 24, 2014 11:29 AM