Bronkhorst Mini CORI-FLOW - Manual (Page 36)

BRONKHORST CORI-TECH B.V.
6.3 Troubleshooting summary general
Symptom Possible cause Action
Red LED is irregular or
continuously on.
Gas bubbles in tube (of liquid meter) Purge to get rid of gas bubbles
Advise: use frequency and/or density signal
to detect if gas or liquid is in the tube.
Too much vibrations Mount isolation rubbers and flexible tubing.
Red LED is continuously on Hardware error Have instrument checked by specialist
Wanted flow is not reached Clogging of the instrument Purge at outlet and/or inlet with dry air if
possible and compare max flow with fixed inlet
pressure to values in the table of the brochure
or using CoriCalc pressure calculations.
No output signal No power supply 1a) check power supply
1b) check cable connection
Output stage damaged due to long lasting
shortage and/or high-voltage peaks
1c) return to factory
Supply pressure too low, or differential pressure
across meter too low
1d) increase supply pressure
Valve blocked/contaminated 1e) connect 0 .. 15 Vdc to valve and slowly
increase voltage while supply pressure is ‘on’.
The valve should open at 7V ± 3V; if not open,
then clean parts and adjust valve (qualified
personnel only)
Piping or filters blocked 1f) clean system
Sensor failure 1g) return to factory
Maximum output signal Output stage damaged 2a) return to factory
Sensor failure 2b) return to factory
Output signal much lower than
setpoint signal or desired flow
Piping or filters blocked/contaminated 3a) clean system
sensor blocked/contaminated 3b) clean sensor with a gas or fluid
Valve blocked/contaminated 3c) clean valve
Valve internal damage (swollen seat in plunger) 3d) replace plunger assembly and adjust valve
or return
Incorrect type of gas is used and/or
pressure/diff. pressure is to low
3e) try instrument on conditions for which it was
designed
Flow is gradually decreasing
Condensation, occurs with NH
3 , hydrocarbons
such as C H ,C H
3 8 4 10 etc.
4a) decrease supply pressure and/or heat gas
to be measured
Valve adjustment has changed 4b) see ‘1e’
Oscillation Supply pressure/diff. pressure too high 5a) lower pressure
Pipeline too short between pressure regulator
and mini CORI-FLOW
5b) increase length or diameter of piping
upstream
Increase between pressure regulator and mini
CORI-FLOW
External vibration is present 5c) Remove external vibration
Valve sleeve or internals damaged 5d) replace damaged parts and adjust valve,
see ‘1e’ or return to factory
Controller adjustment wrong 5e) adjust controller
Software like FLOWPLOT can be used to do
this. Please contact the distributor for details.
Unstable upstream pressure
Small flow at zero setpoint Valve leaks due to damaged plunger or dirt in
orifice
6a) clean orifice and/or, when replacing plunger
assembly, see ‘1e’
Pressure too high or much too low 6b) apply correct pressure
Zero procedure not done or with gas in the tube 6c) Purge and Zero the instrument
High flow at zero setpoint Damaged diaphragm (only applicable to valves
with membrane)
7a) replace membrane seal
Zero procedure not done or with gas in the tube 7b) Purge and Zero the instrument
Disturbances in the flow Gas in the system 8a) Purge the system
Expansion of liquids to gasses 8b) Check properties fluid used
Advise: use frequency and/or density signal
to detect if gas or liquid is in the tube
Calibration error Zero procedure not done or with gas in the tube 9a) Purge and Zero the instrument
Gas in the system 9b) Purge the system
Measure time to short 9c) Measure long enough to get a reliable
measurement
Right reference instrument 9d) The mini CORI-FLOW is a mass-flow
meter/controller and should not be checked with
a volume-meter.
Totalization error Pulsating or fast changing flow Used special CORI-FILL (> 8V16) firmware
specially optimized for totalizing flow.
(Use dampener to stabilize inlet pressure.)
Note: For other (more specific) problems see also troubleshooting parts in other documents.
page 36 9.17.050