Vega VEGAFLEX 81 - Treatment of measurement errors

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8 Diagnostics and service
VEGAFLEX 81 • Modbus and Levelmaster protocol
42283-EN-140430
Error Cause Rectication
4 … 20 mA signal
missing
– Electrical con-
nection faulty
– Check connection according to
chapter "Connectionsteps" and
if necessary, correct according to
chapter "Wiring plan"
– Voltage supply
missing
– Check cables for breaks; repair if
necessary
– Operating volt-
age too low or
load resistance
too high
– Check, adapt if necessary
Current sig-
nal greater than
22 mA or less
than 3.6 mA
– Electronics
module in the
sensor defec-
tive
– Exchange the instrument or send it
in for repair
The below tables show typical examples for application-relevant
measurement errors. There are two measurement errors:
•
Constant level
•
Filling
•
Emptying
The images in column "Errorpattern" show the real level with a bro-
ken line and the level displayed by the sensor as a continuous line.
1
2
Level
time
0
Fig.26:Thebrokenline1showsthereallevel,thecontinuousline2showsthe
level displayed by the sensor
Note:
•
Wherever the sensor displays a constant value, the reason could
also be the fault setting of the current output to "Hold value"
•
In case of a too low level indication, the reason could be a line
resistance that is too high
Treatment of measure-
ment errors