Intek 200 - Manual (Page 4)

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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 rate at which heat is 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
method.
Nonintrusive transducer Example of Example of
(TU) single probe dual probe with
with NPT fitting flange fitting
1.3 PRECAUTIONS
!! CAUTION: Throughout the manual this caution notation indicates
that failure to execute the accompanying instructions
may cause the instrument or external equipment to
malfunction.
!! WARNING: A warning indicates that failure to execute the
accompanying instructions may cause permanent
damage to the instrument or external equipment.
1. Use proper input power — Check the label on the transmitter 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.