Abstract: A method for detecting component defects of an analog signal processing circuit, especially for a measurement transmitter. A test signal TS is generated at a first test point TP1 and an associated response signal RS tapped at a second test point TP2 and evaluated in a digital unit. In the evaluation, individual amplitude values of the response signal RS are compared with predetermined, desired values. In the case of significant deviations, a defect report is generated.

Abstract: A method for detecting component defects of an analog signal processing circuit, especially for a measurement transmitter. A test signal TS is generated at a first test point TP1 and an associated response signal RS tapped at a second test point TP2 and evaluated in a digital unit. In the evaluation, individual amplitude values of the response signal RS are compared with predetermined, desired values. In the case of significant deviations, a defect report is generated.

Abstract: This invention relates to a measuring device for process technology, to be used in measurement and/or cleaning and/or calibration installations in the area of process automation, for measuring pH-values and/or redox potentials and/or other process parameters, and has a central unit, with which at least one measurement module is connectable. Every measurement module is selectable by the central unit by a selection line assigned thereto.

Abstract: The invention relates to a method for registering a measured variable of a measured medium via a measurement path having a sequence of signals, wherein, apart from an original signal of the sequence, each signal of the sequence is a function of a preceding signal of the sequence, at least one signal of the sequence is transformed as a function of the measured variable by interaction with the measured medium, wherein a time variation is impressed on at least a first signal of the sequence, and a second signal, which is present in the sequence of signals at any location after the first signal, is formed by integration of a signal directly preceding the second signal, wherein, additionally, for ascertaining the measured variable, it is assumed, that the measured variable remains essentially constant during the integration.

Abstract: In a method for ascertaining burden resistance for a measurement transmitter, which is supplied with voltage via a first line-pair and which transmits a variable electrical-current signal via an electrical-current loop to a control system via a second line-pair, a test-voltage signal is capacitively coupled into the electrical-current loop and an associated electrical-current signal evaluated. An instantaneous value of the burden resistance is ascertained from a characterizing feature of the electrical-current signal, especially an RC time constant. Thus, already at start-up of a measurement transmitter, a burden resistance, which is too high, can be detected.

Abstract: A two-part sensor composed of a sensor head and a sensor-head counterpart, testing is performed as to whether a correct sensor head is connected with the sensor-head counterpart.

Abstract: In a method for encrypting data in a network of process automation technology, the data are encrypted in a control unit, which is connected with the network, in a separate, exchangeable software module.

Abstract: A fluid power valve arrangement (10) with at least one solenoid valve (10) whose solenoid (14) is connected or able to be connected via only two control lines (11 and 12) with an electrical control and/or communication device (13). The solenoid valve (10) has integrated in it a non-volatile storage means (20) containing identification data of the solenoid valve (10), and furthermore a modulator means (17) for modulation data of the solenoid valve (10) in the two supply lines (11 and 12). The control and/or communication device (13) possesses a demodulator means (24) for demodulation of the modulated data.

Abstract: A measuring device for process technology, having a central unit for the connection of different measurement modules, with the central unit containing a central power supply, to which the measurement modules can be connected. In the measurement module a module power supply is provided, which, from the central power supply, generates one or more supply voltage(s) (V_2, V_3) required by the measurement module. For this purpose, the module power supply has a transformer, a rectifier circuit, or also a switching power supply.

Abstract: A measuring device for process technology, having a central unit for the connection of different measurement modules with the central unit containing a central power supply, to which the measurement modules can be connected. In the measurement module a module power supply is provided, which, from the central power supply, generates one or more supply voltage(s) (V_2, V_3) required by the measurement module. For this purpose, the module power supply has a transformer, a rectifier circuit, or also a switching power supply.

Abstract: This invention relates to a measuring device for process technology, to be used in measurement and/or cleaning and/or calibration installations in the area of process automation, for measuring pH-values and/or redox potentials and/or other process parameters, and has a central unit, with which at least one measurement module is connectable. Every measurement module is selectable by the central unit by a selection line assigned thereto.

Abstract: A symmetrically wired device and a process for measurement of the concentration of ions, especially hydrogen (H+) ions, in a measurement liquid. The device comprises a pH-sensitive measurement electrode, a reference electrode and a comparison electrode, all located in the measurement liquid and which places the measurement liquid at a definable ground reference. The device forms a difference signal referenced to the ground reference from the difference between a measurement signal (?pH) of the measurement electrode and the reference signal (?ref) of the reference electrode. The difference signal is dependent on the ion concentration in the measurement liquid. The device compensates for the noise potential (?chem) arising between the comparison electrode and the measurement electrode by setting a reference potential (?bez) on the comparison electrode, such that ?ref assumes a zero value.

Abstract: A design for constructing an input circuit to receive and process an electrical signal, such as a voltage signal from a voltage source, where the input circuit has an extremely high resistance of at least 1011 ohms and is located on a printed circuit board. A first area of the printed circuit board carrying components of the input circuit is separated from a second area surrounding or contiguous to it by a channel-shaped recess to preserve the high resistance of the circuit even under operating conditions and at high relative humidity. The circuit is configured in such a way that the channel-shaped recess terminates in the interior of the printed circuit board and is extended in the direction of the thickness of the printed circuit board immediately up to a moisture-impermeable barrier layer which underlies the first area of the printed circuit board. The channel-shaped recess and the first area are filled and surrounded by a cohesive moisture-impermeable material.

Abstract: The invention relates to a symmetrically wired device and a process for measurement of the concentration of ions, especially hydrogen (H+) ions, in a measurement liquid. The device comprises a pH-sensitive measurement electrode which is located in a measurement liquid, a reference electrode located in the measurement liquid, a comparison electrode which is located in the measurement liquid and which places the measurement liquid at a definable ground reference. Moreover, the device comprises means for forming a difference signal referenced to the ground reference from the difference between a measurement signal (&phgr;pH) of the measurement electrode and the reference signal (&phgr;ref) of the reference electrode. The difference signal is dependent on the ion concentration in the measurement liquid.

Abstract: The invention relates to a design for constructing an input circuit to receive and process an electrical signal, such as a voltage signal from a voltage source, specifically from a sensor, such as an electrochemical, inductive or optical sensor, where the input circuit has an extremely high resistance of at least 1011 ohms and is located on a printed circuit board (4), where a first area (2) of the printed circuit board (4) carrying components (6, 8) of the input circuit is separated from a second area (12) surrounding or contiguous to it by a channel-shaped recess (10); to preserve the high resistance of the circuit even under operating conditions and at high relative humidity, the circuit under the invention is configured in such a way that the channel-shaped recess (10) terminates in the interior of the printed circuit board (4) and is extended in the direction of the thickness of the printed circuit board (4) immediately up to a moisture-impermeable barrier layer (20) which underlies) the first area (2) o