Abstract: In order to make it possible to go to and to find a field device in a process plant in the shortest possible time, there is provided a fixed-position device and a mobile device. The fixed-position device is associated with the field device and comprising at least one processing unit, one communication device with an antenna for wire-free communication, and a non-volatile memory. Details relating to the position of the installation location of the field device are stored in the non-volatile memory such that they can be called up. The mobile device is equipped with a processing unit, a keyboard, a display unit for visualizing the details relating to the position of the installation location of the field device and a communication device which corresponds to the communication device in the fixed-position device and has an antenna for wire-free communication.

Abstract: A sampled data system for computing the amplitude of a signal received from a vibration sensing probe minus the fundamental frequency associated with the running speed of a rotating machinery shaft. This signal is known as the Not 1X waveform and variations in its amplitude can signal problems with bearings, rotors, cracks or mechanical looseness, and/or fluids of the rotating machine. The amplitude of the Not 1X waveform can be provided in either peak to peak amplitude, peak amplitude, absolute average or root mean square.

Abstract: A method of initializing a pluggable electrical unit in a modular system that has a base unit and at least one pluggable electrical unit connected via an interface. Each pluggable electrical unit has module electronics and a read-only memory with clearly identifying identifiers. The interface is equipped with a variable resistor in a feed line. The connection between the base unit and the pluggable electrical unit is established initially only partially, and only to the read-only memory, after switching on the power supply to the pluggable electrical unit. After that, the pluggable electrical unit is identified and, in accordance with the identity of the pluggable electrical unit, the full connection or full isolation between the base unit and the pluggable electrical unit is established.

Abstract: There is disclosed a measurement mechanism for differential pressure measurement. The mechanism has two housing portions with flanges. A differential pressure sensor is force-fit between the two flange faces. An electronics board is connected to the differential pressure sensor by means of a force-fit electrical contact.

Abstract: The invention relates to a device for locking a pluggable electrical unit in an enclosure of an electrical base unit, the pluggable electrical unit having at least one arresting element, which engages in a mating arresting element in the enclosure of the base unit in such a way that the physical removal of the pluggable electrical unit is prevented in the locked state. For the slot-dependent detection of the actuation of locking elements on the part of the base unit, it is proposed to arrange the arresting element (21) such that, in the rest position, it is concealed by a movable covering (24) in such a way that the arresting element (21) is only accessible once the covering (24) has been removed. The covering (24) is in operative connection with an electrical switching contact (25), each position of the covering (24) deviating from the rest position triggering the switching contact (25). The covering (24) can only be brought into the rest position in the locked state of the pluggable electrical unit (2).

Abstract: A differential pressure sensor has a first and a second measuring chamber. Each measuring chamber is limited by a rigid carrier plate and a diaphragm plate, which is formed in the region of the measuring chamber as a pressure-sensitive measuring diaphragm. To design the differential pressure sensor to be resistant to overloading, the carrier plate is arranged between a first and a second diaphragm plate and has congruent concave depressions on opposite sides in the plane of the plate. The depressions are connected to one another by a central duct, penetrating the carrier plate perpendicularly to the plane of the plates. In the region of the measuring chambers, the diaphragm plates are formed congruently in relation to the depressions as pressure-sensitive measuring diaphragms. The measuring chambers are coupled to one another by a ram guided axially movably in the duct.

Abstract: A method and apparatus for aligning the axis of a mirror of a carbon in ash sensor. The method first executes a series of steps that causes a stepper motor connected to an axis of the mirror to move the mirror through a first coarse alignment procedure and then executes a second series of steps that that moves the mirror through a second fine alignment procedure.

Abstract: The invention relates to a field bus arrangement with a field bus distributor (11) for mounting in the area (1) at risk of explosion, for feeding a plurality of field devices (121 to 12n), arranged in the area (1) at risk of explosion, via intrinsically safe electric circuits (13) from at least one high-energy voltage source (21) arranged in the area (2) not at risk of explosion. For this purpose, in the area (2) not at risk of explosion, a field bus coupler (22) arranged in the area (2) not at risk of an explosion and having three electric circuits which are DC-isolated from one another is provided.

Abstract: A N pulse variable frequency drive for driving two or more motors that is the combination of two or more variable frequency drives with each drive driving an associated one of the two or motors. One application is a decanter centrifuge which has a main motor to drive the bowl and a back motor to drive the conveyor. One of the two variable frequency drives drives the main motor and the other drive drives the back motor. The variable frequency drives are connected to a common buss and to a N pulse phase shifting transformer.

Abstract: A differential pressure sensor has a first and a second measuring chamber. Each measuring chamber is limited by a rigid carrier plate and a diaphragm plate, which is formed in the region of the measuring chamber as a pressure-sensitive measuring diaphragm. To design the differential pressure sensor to be resistant to overloading, the carrier plate is arranged between a first and a second diaphragm plate and has congruent concave depressions on opposite sides in the plane of the plate. The depressions are connected to one another by a decentered duct, penetrating the carrier plate perpendicularly to the plane of the plates. In the region of the measuring chambers, the diaphragm plates are formed congruently in relation to the depressions as pressure-sensitive measuring diaphragms. The measuring chambers and the duct are filled with an incompressible fluid.

Abstract: A method for determining the measure of control provided to a process by a control system. The determines process model parameters for a simple and complex model of the process and uses those parameters along with the value of the process variable and the final control element position to predict the off control data. The method also uses the process model parameters to determine the optimal tuning and then forecasts the optimal process performance from the predicted off control data and the determined optimal tuning.

Abstract: There is described a capacitive differential pressure sensor made using glass-silicon technology with a diaphragm plate of silicon, which is arranged between two carrier plates consisting of glass. The diaphragm plate has pressure-sensitively deflectable regions, which are respectively provided with a capacitor arrangement. The capacitor arrangement is connected to a measured-value processing device through connecting conductors. To improve the ratio of the measuring capacitances to the parasitic capacitances brought about by the connecting conductors, the diaphragm plate is outside the pressure-sensitively deflectable region the substrate of an electronic circuit which comprises at least one input stage of the measured-value processing device.

Abstract: A method for recording and removing the bipolar bias from a vibration input signal. The signal is a time varying signal where the bipolar bias has an amplitude which is many times greater than the amplitude of the time varying waveform of the signal that represents the vibration of the machine. In calculating the level of the bipolar bias the method approaches a predetermined dead band asymptotically and in stable manner. The determination of the bipolar bias level occurs when the next event has occurred and the time for that determination is much shorter than the time between occurrence of the events.

Abstract: There is described a differential pressure sensor made using glass-silicon technology with a diaphragm plate arranged between two carrier plates. To achieve a high resolution at the beginning of the measuring range in conjunction with high overload resistance, the measuring diaphragm plate of the sensor has for a prescribed measuring range within the same measuring chambers a plurality of mutually independent deflectable regions as measuring diaphragms. Each such region acts as a part-sensor with a part-measuring range. The part-measuring ranges of the part-sensors overlap and in total are equal to the prescribed measuring range of the differential pressure sensor. The displacement of the measuring diaphragm of each part-sensor is mechanically limited outside its part-measuring range by the carrier plates.

Abstract: A method for determining the DC current flowing through an AC power meter. The internal impedance of the distribution transformer is first sensed, then the DC voltage in the AC voltage waveform is measured and finally the measured DC voltage is converted to DC current.

Abstract: A method and apparatus for analyzing and signal conditioning the pulsation signal derived from combustion of fuel in a turbine. There are one or more user defined frequency bands and the method and apparatus provides a digital signal for the true RMS value of each of the user defined bands. Turbine protection logic has as its input the digital true RMS values for each such band and inspects that value to determine if the frequencies in that band exceed a predetermined level for a predetermined period of time.

Abstract: A gas analyzer having an analysis or sensor unit and having an electronic processing unit, and a method for operating such a gas analyzer. In order to achieve substantially improved safety both in handling corrosive and/or combustible and/or toxic gases in a not potentially explosive atmosphere (ex-free atmosphere), and in the operation of such an analyzer in an ex-atmosphere, the analysis or sensor unit as such is of non-explosive configuration and is arranged in a gas tight chamber through which a toxic and/or corrosive and/or combustible gas flows and around which a second chamber is arranged.

Abstract: A method and apparatus for calculating the volume fraction of carbon in the fly ash using a carbon in fly ash sensor that has a resonant cavity. The method first determines the volume fraction of ash in the fly ash. The method then determines the real and imaginary components of the dielectric constant of a mixture of pure carbon and pure fly ash, and the transmission factor of a signal from the oscillator in the sensor transmitted through the cavity due to absorption by material in the cavity. The method then determines the volume fraction of carbon in the fly ash by using the volume fraction of ash, the real and imaginary components of the pure mixture dielectric constant, the absorption transmission factor and the length of the cavity, the speed of light and the frequency of the oscillator.

Abstract: A method for measuring NOx having a specific discharge lamp. The method controls a photometric analysis device, in which an electrically rotatable filter wheel or shutter wheel is used to change various shutters and/or filters in a beam path with beam source, cuvette and detector. The filter and/or shutter wheel is controlled in such a way that the measurement time is greater than the transfer time. This control improves the detection limit of the NOx resonance absorption method.

Abstract: A gas analyzer having an analysis or sensor unit and having an electronic processing unit, and a method for operating such a gas analyzer. In order to achieve substantially improved safety both in handling corrosive and/or combustible and/or toxic gases in a not potentially explosive atmosphere (ex-free atmosphere), and in the operation of such an analyzer in an exatmosphere, the analysis or sensor unit as such is of non-explosive configuration and is arranged in a gas tight chamber through which a toxic and/or corrosive and/or combustible gas flows and around which a second chamber is arranged.