Thermo Fisher Scientific Gmbh

Sergey A Moskalenko

James Kevin Roberts

Tom Lee Erb

Kevin M Johnson

Bruce Herbes

David Gessner

Frederick Cash

Teresa Ainsworth

Lorna Lockman

Gary Dickinson

Doug Schmidt

Scott Eggerth

Robert M Ries

Yuriy Bro

Jeffrey Ferguson

Syed Mohammad Hamzauddin

Process metal detection system

A metal detector used for identifying contaminants in packages on a conveyor. The detector includes coils a search head and an analog to digital converter generating a reactive signal and a resistive signal in response to the presence of a contaminant. During a learning mode a sample product passes through the metal detector providing a representative product effect signal which is stored by the reactive learn memory and the resistive learn memory. The learn memory values provide a reference value subtracted from each product signal during a normal production cycle, canceling the product effect caused by contaminants in individual packages. The product effect is monitored during successive cycles composed of a series of packages undergoing normal inspection by the metal detector. A tracking processor averages the product effect signal produced by the individual packages and continuously updates a product effect trend signal that is subtracted from each product signal.

Apparatus and method for automatic product effect compensation in radio frequency metal detectors

A metal detector () used for identifying contaminants in products () introduced into the metal detector by a conveyor. The detector () includes coils (), a search head () and an analog to digital converter () that generates a reactive signal () in response to the presence of a contaminant in the region of the coils. A calculation processor () receives the reactive signal () along with the value of the conveyor speed () to determine a calibration ratio R that is unique to each individual metal detector (). The optimum frequency F for metal detector operation is equal to the conveyor speed () divided by the ratio R. The ratio R simplifies the selection of filter parameters () for a speed filter () which correlates the conveyor speed () with the frequency F so as to deliver an optimized signal to the detection algorithm () used to determine the presence of a contaminant based on the signal () derived from the coils ().

Speed filter calibration apparatus and method for radio frequency metal detectors

A contaminant detection machine () including a conveyor () which causes an object under inspection () to pass through a plane () of emitted x-ray radiation. The plane is generated by an x-ray tube () that emits a lateral beam, thereby permitting the distance () between the x-ray tube and the object under inspection to be reduced. A photo diode arch mounting assembly () is placed above the object under inspection and is mated to a collimator assembly () that also serves as the mounting bracket for the x-ray generation assembly (), thereby preserving optical alignment between the photo diode detector array () and the emitted x-ray plane (). The detector array () scans the object under inspection () so as to produce a continuous series of discrete lines, each line being analyzed by an image processing unit () to determine the presence or absence of a contaminant. The conveyor () passes over a pair of slider bed surfaces () which are mounted in a hinged manner such that the leading edge () of one surface () is parallel to and spaced apart from the trailing edge () of the other surface (), thereby creating a gap that is coplanar with the collimation slot () and the emitted x-ray plane (). Each bed surface () is rigidly constrained within open ended mounting brackets (and) yet can be removed by hand without the use of tools. Similarly, the conveyor () is supported by a roller assembly () that includes a tracking block () and pivot pin () which permits the roller assembly to be mounted to and removed from flip up mounts () by hand and without the need of tools. Graphical user interfaces (and) permit a user to operate the machine () by means of a liquid crystal display touch screen ().

Contaminant detector for food inspection

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Maple Grove, MN, United States of America

Sergey A Moskalenko