Thermo Scientific APEX 100 User Manual page 397

Glossary
Term
QAT
QNR
RAM
Reject device
RFI
RO
R threshold
RTU
R/W
Rx
Search head
SF-NB
SF-WB
Speed filter
Thermo Scientific APEX User's Guide
Definition
The Quality Assurance test—one of the detector's
quality-control functions.
Quadrature noise-reduction filter
Random-access memory
Any mechanical device downstream of the search head
that allows contaminated products to be separated
from uncontaminated products. In a typical conveyor
application, "Reject 1" is the main reject device and
"Reject 2" the secondary reject device.
Radiated frequency interference
In the Modbus registers, a read-only register.
Electrically conductive materials and many food
products, by nature, are electrically conductive. Salt-
and moisture-content combine to produce resistive
effects that must be overcome in order to detect small
metallic contaminants. The R threshold is a noise
threshold for resistive signals. Signals above the
threshold usually indicate product or metal
contaminant signals. Excessive resistive signals could
indicate external noise (such as VFD and EMI noise),
ground loops, static, and so on is present in the area
around the metal detector.
Remote terminal unit
In the Modbus registers, a read/write register.
Pharmaceutical application
The large rectangular box with a hole in the middle
through which products are passed to be tested for the
presence of metallic contaminants. Inside, the
magnetic field created by a pair of balanced coils is
disturbed by the passage of metal, allowing the
detector's circuitry to tag the product as
contaminated.
Speed filter–narrow band
Speed filter–wide band
The speed filter is a narrow-band pass filter that
rejects most background noise, but still allows a
maximum metal signal from the search head to be
processed by the detector.
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