Dwyer TFM-LP - Manual (Page 29)

F-20-TF-L, pg. 29 of 30
Symptom Possible Cause Method of Correction
Flow indication is not
linear and output too
low at lower flows Attempting to measure flows
below the specified
minimum for the unit
Liquid is too viscous
Entrapped air or gas
Mechanical sensor
assembly damaged
Use higher flow rates.
Best results are obtained
with liquids that have a
viscosity of 10cS or less.
Contact Dwyer Customer
Service for further
information.
Remove entrapped air (see
section C2).
Unit must be returned for
repair (see Section D3).
Flow indication
“bounces” or
fluctuates Flow is actually fluctuating
Not using the fittings
supplied by the
manuafacturer
Entrapped air or gas
Turbulence in tubing or
sensor
Fluctuating input power
Mechanical sensor
assembly damaged
Correct flow source to
obtain steady flow.
Use the supplied fittings.
Remove entrapped air (see
section C2).
Straighten the inlet tubing or
lengthen it to at least 6”
(150mm) (see section B3).
Correct the power source or
change to a regulated
supply.
Unit must be returned for
repair (see Section D3).
Flow indication is
fixed at one value The maximum rated flow for
the unit is being exceeded.
Output circuits may be
damaged
Reduce the flow.
Unit must be returned for
repair (see Section D3).