Instructions for Use
– SCHMIDT
®
Flow Sensor SS 20.600
Page 33
The stick may only be moved with great care back and forth parallel to the
chip surface to rub off the dirt. If necessary, use several cotton swabs.
Before recommissioning, the sensor head must be completely dry. The
drying process can be accelerated by gently blowing.
If this procedure does not help, the sensor must be sent to
SCHMIDT
Technology
for cleaning or repair.
Eliminating malfunctions
The following Table 9 lists possible errors (error images). A description of
the way to detect errors is given. Furthermore, possible causes and
measures to be taken to eliminate errors are listed.
Causes of any error signaling have to be eliminated imme-diately.
Significant exceeding or falling below the permitted operating
parameters can result in permanent damage to the sensor.
Error image
Possible causes
Troubleshooting
Problems with supply voltage
U
B
:
No U
B
present
U
B
has wrong polarity
U
B
< 15 V
Sensor defective
Plug-in connector of cable
screwed on correctly?
Supply voltage connected
to control?
Supply voltage at sensor
plug available; cable break?
Sufficient power supply?
Send sensor in for repair
No LED is lit
All signal outputs at zero
Start sequence is repeated
continuously (all LEDs red
- yellow - green)
U
B
unstable:
Power supply unable to
supply switch-on current
Supply overloaded by other
devices
Wire resistance too high
Is supply voltage at sensor
stable?
Is supply power sufficient?
Voltage losses over cable
negligible?
Sensor element defective
Return sensor for repair
Supply voltage too low
Increase supply voltage
Supply voltage too high
Reduce supply voltage
Electr. temperature too low
Increase operating
temperature of environment
Electr. temperature too high
Lower operating temperature
of environment
Medium temperature too low Increase medium temperature
Medium temperature too high Lower medium temperature
