BRONKHORST EL-FLOW Select Series - Page 48

Bronkhorst®
Instruction Manual EL-FLOW® Select 9.17.099F48
Symptom
Possible cause
Action
Measured value rises, but never
reaches setpoint
Piping, filters and/or control valve
clogged or blocked
· Flush fluid system with clean, dry air. If
problem persists, contact Bronkhorst.
· For external proportional control valves:
supply 0…15 Vdc and operational inlet
pressure to valve and slowly increase
voltage. If valve does not open, clean parts
and re-adjust valve
Inlet pressure too low
Increase inlet pressure
Outlet pressure too high
Check/decrease outlet pressure
Process outlet blocked
Check process outlet and downstream piping
Measured value or output signal
(much) lower than setpoint
Inlet pressure or differential
pressure too low
· Increase inlet pressure
· Use instrument in conditions it was designed
for
Process gas condensation
Decrease inlet pressure or increase gas
temperature
· Piping, filters and/or control
valve clogged or blocked
· Sensor blocked or contaminated
Flush fluid system with clean, dry air. If problem
persists, contact Bronkhorst.
Supplied fluid type does not match
configured fluid type
Supply equipment with other fluid or change
fluid type in instrument configuration
Measured value or output signal
indicates a flow, while there is
none
Mounting orientation and/or
ambient conditions changed
significantly
· Use instrument in conditions it was designed
for
· Adjust zero point (see Adjusting zero point)
System leakage
Check the system for leakage. Follow vendor
instructions when installing third party
components (e.g. adapters, tubing, valves)
Continuous maximum measured
value or output signal
Inlet pressure too high
Check inlet pressure
Valve fully open
· Close valve
· Check if control valve is in Safe State
(normally open valves); remove cause if
necessary (see Valve Safe State)
Sensor failure
Return equipment to factory