Intek 200 - Manual (Page 19)

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SECTION 4 ! MAINTENANCE
4.1 GENERAL MAINTENANCE
Certain precautions should be taken to insure proper performance of all models of flow instruments.
Since the measurement technique involves a signal resulting from heat transfer to the flowing medium,
care should be exercised to prevent build-up of varying layers on the walls of the transducer. Layers
such as bacterial growth, dried paints, gas bubbles and non-solubles can result in measurement below
actual flow rates. Periodic checks and cleaning should be performed to insure a clean pipe or probe
surface.
It should be part of normal maintenance procedure to check the system for proper functioning.
Experience and other observable conditions should be utilized to determine the frequency of inspection.
Long term drift in the unit calibrations is not expected, but if a recalibration is required, refer to
SECTION 3.4.3. To test the flow switch action, the flow rate should be reduced below (for low flow
switch) or raised above (for high flow switch) the switching level. Then check and insure relay action
and continuity of the shut down or warning circuits which it operates.
The joints of all intrusive probes tips should be inspected for wear and corrosion.
4.2 FLOW CALIBRATION ADJUSTMENT
Occasionally over time or due to process condition changes a slight realignment of the calibration may
be required to maintain the desired indication accuracy. Periodically verify the instrument calibration
by comparing the indication versus another accurate flow measurement or against a trusted primary
standard. After characterizing the drift tendencies and considering the accuracy requirements, determine
a regular calibration verification cycle. Otherwise, an annual verification is recommended for typical
installations. Calibration instructions are located in SECTION 3.4.3 of the operation manual.
4.3 SPARE PARTS
The transducer and transmitter electronics are calibrated as a set, and cannot be randomly interchanged
with others. For critical applications, a complete spare flow meter (transducer and electronics) should be
stocked. A spare transducer can be stocked, if it is ordered and calibrated at the same time as the flow
meter. A spare electronics unit can be ordered anytime; this requires that special software also be
purchased in order to upload transducer specific calibration parameters. Contact the factory for more
information.
There are also two fuses which can be stocked: Wickmann part numbers 3740250041 (F2) and
3740160041 (F1) respectively, or equivalent.
4.4 TRANSDUCER & TRANSMITTER FUNCTIONAL TESTS
A test of the Rheotherm instrument functional operation can be performed in three phases:
1. Transducer continuity check.
2. Transducer isolation check.
3. Electronic circuit board check.