Thermo Scientific APEX 100, Руководство пользователя

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Page 370
Thermo Scientific APEX User’s Guide
Discussion of Product Requirements
The IXR function may overcome some of the common pitfalls of phasing, but it requires
that products are fairly consistent as far as the signal they produce while travelling
through the search-head aperture. The products themselves also need to be consistent
in content, volume, and presentation (orientation). For example, a product that has
varying fat- or salt-contents, may not produce the consistent signal the IXR function
requires to detect very small amounts of metallic contamination.
The volume of the product is also important, because a larger volume of product will
produce a larger signal. As a result, the volume of the product should be consistent to
get the best performance from the IXR function. Product presentation is another factor
that is crucial to IXR function. Presentation includes the shape and orientation of the
product as it passes through the aperture. For example a product that is cube-shaped
should have guide rails to insure that it passes through the aperture parallel to belt and
through the same part of the aperture each time. Similarly, a rectangular box must pass
through the aperture with the same orientation as used when calibrating the product.
The IXR function requires a photo eye and a constant speed for each product for the
real-time product signal to match the one that is stored in memory during calibration. A
variable-speed conveyor can be used, but changing the speed means the IXR function
must be recalibrated. Please note, however, that the APEX has an IXR tracking feature
that allows small and gradual speed changes over time to be accommodated. In
addition, the IXR-tracking feature allows the APEX to accommodate gradual changes in
the product signal over time that occur due to slight variations in temperature, belt
speed, or other non-contaminant factors. This feature often eliminates false rejects due
to this type of variation in the product signal.
The Next Step
Before you can start using the IXR function, you must do the following.
1)
Set the proper pack length, “detection no-pack” distance, photo-eye distance, and
photo-eye registration. These four parameter must be set for the IXR function to
work properly.
2)
Enable the IXR function.
3)
Calibrate the system.
If you encounter problems while setting up the IXR function, please see the
“Troubleshooting” section in this appendix, or contact Thermo Fisher Scientific—as
described in the “Contacting Thermo Fisher Scientific” section at the end of the manual.