Thermo Scientific Oretronic III, Operating & Service Manual

Page: 87 / 152

Maintaining & Troubleshooting
Thermo Fisher Scientific Maintaining & Troubleshooting 4-19
REC-4105 Rev L
10. Place the TMD in Calibrate mode and scroll to the COARSE
display.
11. Using the up VALUE key, increase the COARSE value by 1 and
press ENTER.
12. Place the TMD in Run mode, pass the test tramp through the coils,
and check for a trip.
If the sensitivity is still not correct for your system, repeat Steps 7–
12 of this procedure until it is.
If this procedure does not increase the sensitivity enough, try the
procedures in Finding the Source of Mechanical or Electrical Noise on
page 4-7. For a dual coil TMD, you can also try lowering the transmitter
coil to the minimum height possible (refer to Outline, Mounting and
Assembly, Coil Stand (D07328C-A003).
If these steps do not result in adequate sensitivity, you may need to
change the material type code.
Note
: Adjusting metal sensitivity is performed the same for both double
and single coil detectors.
Detecting small-sized tramp metal, especially small stainless steel tramp
may require changing the material type code used by the TMD. This
may not result in a dramatic sensitivity increase because a reduction of
1/2 in tramp size may result in a reduction of only 1/4 to 1/16 of the
signal; the signal reduction is a function of both size and type.
First, you must determine how well the TMD is working with the current
material type code (which should be 3).
1. Balance the coils using the procedure in Correcting Coil Imbalance
on page 4-4.
2. Scroll to the COIL BAL display and observe the LED bar graph.
3. Increase the COARSE and FINE sensitivity values until 5 LEDs are
lit in the COIL BAL diagnostic display.
This may require a number of cycles of changing and observing.
Changing the
Material Type
Code to Adjust
Sensitivity