Intek 100FS User Manual
Page 4
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Nonintrusive transducer
(TU)
Example of dual probe
with flange fitting
Example of single probe
with NPT fitting
1.2 DESCRIPTION OF OPERATION
Rheotherm flow meters are available with various nonintrusive and intrusive transducer designs, but
they all use the same thermal sensing technique. Two temperature sensors are used
one is in thermal
equilibrium with the fluid and provides a fluid temperature reference, while the second temperature
sensor is located near a heater so that its temperature is slightly above that of the fluid. In a TU
transducer, the temperature sensors and heater are attached to the outside of the flow tube, whereas the
probe transducers have the sensors and heater located in the probe(s) that are inserted into the stream.
The amount of heat removed from the heated sensor by the stream is related to fluid velocity. Hence,
the measured temperature differential between the reference sensor and heated sensor is a function of
flow rate. Intek, Inc. is licensed to use this patented and trademarked flow measurement technique.
1.3 PRECAUTIONS
1.
Use proper input power
Check the label on the electronics for the input power
requirements.
2.
Use reasonable care in handling the transducer. Do not try to disassemble the transducers;
there are no removable parts.
TU
excessive twisting or bending can damage the sensor. The flow tubes are thin-walled
tubing.
Probes (NPT/2I, NPT/I, BF/2I, BF/I, etc.) take care not to bend the probes or damage the
tips. Do not try to remove or turn the conduit junction box.
3.
Check the transducer maximum temperature rating do not operate a transducer at or subject
it to a temperature above its specified limit.
4.
Keep moisture out of the electronic enclosure and sensor junction box. Once cable
connections are made in the junction box, make sure the lid is tightly closed. Seal conduit
lines if they can become wet inside.