Siemens SITRANS FC330 Operating Instructions Manual page 192

Diagnostics and troubleshooting
10.3 Operation troubleshooting
0.15
-0.15
Table 10-1
Flow conditions Fully developed flow profile
Temperature,
medium
Temperature,
ambient
Liquid pressure 2 ± 1 bar
Density
Brix
Supply voltage
Warming-up time 30 min.
Cable length
Table 10-2
Current output
Effect of ambient
temperature
Effect of supply
voltage
Step 4: Improving the application
In the following it is described how to find the causes of a high Zero point standard deviation and
how to improve the installation.
Setting Low flow cut-off
In order to see if the zero point becomes more stable when making changes / adjustments, the
Low Mass flow cut-off (MassFlowCutOff) must be set to 0.0 kg/s.
When Low flow cut-off has been set, it is possible to see the instability directly from the mass
flow in the online window ("View → Process variables")
This information can be used to troubleshoot. For example, tightening the brackets which hold
the sensor, or turning off the pump to check if vibrations from the pump are disturbing the
sensor, etc.
192
Error in % of actual mass flow rate with 95% confidence
(probability)
1.0
0.5
-0.5
-1.0
5% 25%
Actual mass
flow rate
Reference conditions for flow calibrations (ISO 9104 and DIN/EN 29104)
20 °C ± 2 °C (68 °F ± 3.6 °F)
20 °C ± 2 °C (68 °F ± 3.6 °F)
0.997 g/cm3
40 °Brix
Un ± 1 %
5 m between transmitter and sensor
Additions in the event of deviations from reference conditions
As pulse output ± (0.1% of actual flow +0.05 % FSO)
● Display/frequency/pulse output: < ± 0.003%/K act. ± 3.6 °F)
● Current output: < ± 0.005 %/ K act.
< 0.005 % of measuring value on 1 % alteration
50% 75% 100%
FSO (sensors
max. flow rate)
Operating Instructions, 01/2019, A5E44030648-AB
SITRANS FC330