Instructions for Use
– SCHMIDT
®
Flow Sensor SS 20.400
Page 19
8 Service Information
Maintenance
A soiled sensor tip may distort the measured value. Therefore the sensor
tip must be checked for soiling at regular intervals.
If it is soiled or wetted by a liquid, the sensor signals an error via the analog
output (0 V or 2 mA). In this case, clean sensor as described below.
If the error signal does not disappear after cleaning and drying, the sensor
must be sent in to the manufacturer for repair.
Cleaning sensor tip
If the sensor tip is soiled or dusty, it must be carefully cleaned by means
of compressed air (avoid strong pressure impulses!).
If this procedure is not successful, the sensor tip can be cleaned by im-
mersing and washing it in alcohol, which dries without leaving residues
(e.g. isopropyl alcohol).
As soon as the alcohol has been evaporated, the sensor is again ready
for operation.
Do not shake or tap the wet sensor!
Do not try to clean the sensor tip by any type of mechanical
methods. Do not touch the sensor element located in the
chamber head. This may irreversibly damage the sensor.
Do not use strong cleaners, brushes or other objects like
fluffy cloths etc. to clean the sensor tip!
Inappropriate cleaning agents may leave residues on the
sensor element and therefore lead to faulty measurements
or result in permanent damage to the sensor element.
If the chamber head gap of the sensor tip is completely filled
with cleaning agent, accelerate the drying process by blow-
ing it out, if necessary.
!
