Mettler-toledo Ag

Mettler-toledo Gmbh

Cyrill Bucher

Daniel Reber

Jean-Christophe Emery

Hansruedi Künzi

Douglas Bliss

Christoph Trautweiler

Markus Uster

Aaron Skidmore

David Koller

Hansruedi Kuenzi

Hans-Peter Von Arb

Stefan Buehler

Philip R Ouellette

A differential measurement circuit () is implemented in a balance with electromagnetic force compensation. The circuit receives input from two photo currents (I, I) generated by photodiodes (D, D) and generates an output signal proportional to their difference. A switch (SW) controls the flow of current through a node (K) to which the two photo currents are directed, by flipping between two states (z, z) within two phases (t, t) of a time period T. The switch is controlled so a reference current (I) from a voltage or current source (U) is superimposed alternatingly within the time phases on one of the two photo currents which continuously flow into the node. The node lies at the input of an integrator (INT) whose integrator signal (s) can be compared in a comparator (CMP) to a cyclically recurring ramp signal (s) which conforms to the time period. At the output of the comparator, a rectangular-shaped comparator signal (s) can be generated whose duty cycle ratio is defined by the intersection of the integrator signal with the ramp signal and which can be directed to a control input of the switch.

Differential measurement circuit, and balance with force compensation

A multiple force-measuring device, especially a multiple weighing device has at least two force-measuring modules. Each force-measuring module includes a force-measuring cell and a power delivery means. The power delivery means of at least one of the force-measuring modules in this arrangement is connected, directly or through a junction element, to a control cable that is connected to a power supply unit. The force-measuring modules are connected directly to each other through a module-connection cable that transfers electrical power therebetween.

Multiple force-measuring device, force-measuring module, and method for monitoring a condition of the multiple force-measuring device

A force-measuring device () with at least one housing () has an interior space and at least one force-measuring cell () installed therein. At least one parameter characterizing an existing high-frequency electromagnetic field is determined by a sensor () arranged in the interior space or a sensor arranged outside of the housing, the sensor being adapted for detecting high-frequency electromagnetic fields. After an electromagnetic field is detected and compared to a threshold value, a response action of the force-measuring device is triggered if the detected parameter value exceeds the threshold value.

Sensing RF and EM interference of a force-measuring device and adjusting operation accordingly

A method is disclosed for correcting transfer errors of an analog amplifier that occur following a jump in the amplifier input signal caused by switching. A measuring device includes at least one sensor as well as a signal-processing unit connected to the sensor and analog amplifier. The signal-processing unit includes at least one modulator and/or a multiplexer, an analog amplifier and at least one processing stage following the analog amplifier in the circuit chain. The processing stage, dependent on the point in time when the switching jump occurs, is separated from the latter during a predetermined timeout phase duration by means of a switch that is arranged between the analog amplifier and the processing stage and is controlled by a timeout controller, and/or dependent on the point in time when the switching jump occurs, said processing stage is blocked by a timeout controller during a predetermined timeout phase duration.

Method of correcting the output signal of an analog amplifier, amplifier module and measuring device

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Uster, Switzerland

Cyrill Bucher