Measuring device for process and automation technology

Abstract

Measuring device for process and automation technology for detecting a physical quantity, with a sensor element, an electronic unit (10) and a signal output (3), wherein the electronic unit (10) is arranged in a housing (2) and serves to evaluate and / or process the measurement signals generated by the sensor element, and wherein the signal output (3) is designed as a standardized connector (3) with contact pins (3a) projecting from the housing (2), via which the measuring device (1) is supplied with energy and the generated measuring signals can be tapped off by a higher-level control unit, wherein the connector (3) comprises an adjusting screw (20) for influencing the electronic unit (10), which is arranged parallel to the longitudinal direction of the contact pins (3a) and can be operated by means of a screwdriver, wherein the adjusting screw (20) is displaceable in the longitudinal direction, wherein the adjusting screw (20) is rotatable about its axis and wherein the electronic unit (10) comprises a potentiometer (11) and the adjusting screw (20) influences this potentiometer (11) by rotational and / or longitudinal movement.

Description

Measuring device for process and automation technology

[0001] The invention relates to a measuring device for process and automation technology for detecting a physical quantity.

[0002] A measuring device of the type in question essentially comprises a sensor element, an electronic unit for evaluating and / or processing the measurement signals generated by the sensor element and an electrical interface via which the measuring device is supplied with energy and the generated measurement signals can be tapped by a higher-level control unit.

[0003] The sensor element, also known as a transducer, is used to detect and convert a physical measured value of a process value into a measurement signal. In process engineering, the transducer is used in particular to detect pressure, temperature, flow rate, or fill levels of a medium in a container. There are also other applications in automation technology, examples of which include optical, capacitive, and inductive proximity switches and sensors.

[0004] The electronics unit is housed in a housing. The sensor element and a display and control unit are often located in or on the housing, although some measuring devices do not have a display and control unit, or the sensor element is located remotely.

[0005] Typically, the signal output is designed as a standardized connector with contact pins protruding from the housing. Connectors in accordance with DIN EN 61076 in M12 or M8 format are often used. These connectors are then connected to a corresponding, standardized mating connector to connect the measuring device to a control unit, such as a PLC, or to supply it with power.

[0006] These measuring devices output the measurement signals via the signal output either as an analog current or voltage signal or as a binary switching signal. To output a switching signal, the measuring device must be configured with the appropriate switching thresholds, also known as switching points. In addition to switching points, hysteresis values ​​or limit values ​​may be important as additional parameters. These data are usually set either via the display and control unit on the measuring device or, in the case of a so-called transmitter device and therefore no control unit, via the connected control unit.

[0007] One possibility for setting the switching point in pressure gauges is disclosed in the applicant's German patent DE 102 46 874 B4. Here, a parameter of the gauge is adjusted using a rotatable adjustment ring, which is designed as a separate housing sleeve.

[0008] Furthermore, DE 10 2005 049 483 A1 discloses an electrical plug in which an opening is formed within a plug connection into which an actuating element, for example the tip of a screwdriver, can be inserted to activate write protection.

[0009] The object of the invention is to propose a measuring device in question with an alternative setting option for entering parameters.

[0010] The object is achieved by a measuring device having the features of claim 1. Advantageous embodiments of the invention are specified in the subclaims.

[0011] According to the invention, the connector comprises an adjusting screw for influencing the electronics unit. The adjusting screw is arranged parallel to the longitudinal direction of the contact pins and can be operated using a screwdriver. The adjusting screw can be rotated about its longitudinal axis and / or displaced along its longitudinal direction, so that both rotary and linear movement of the adjusting screw is possible. Screwdrivers are understood to be all hand-held tools intended for screwing screws into or out of materials, in particular slotted, Phillips, hexagon, and Torx screwdrivers. Furthermore, the electronics unit comprises a potentiometer, which influences the adjusting screw through its rotary and / or longitudinal movement. This allows parameters to be easily set on the measuring device.

[0012] The core of the invention is therefore to provide an adjustment option on the measuring device that does not require an additional device opening. Especially for measuring devices with stainless steel housings, some of which are used in harsh industrial conditions or, for example, are cleaned with hot and aggressive cleaning fluids under high pressure due to special hygiene regulations, it is advantageous to keep the number of housing openings that need to be sealed as small as possible.

[0013] Placing the adjusting screw in the connector therefore has the advantage that, once a corresponding mating connector has been plugged in, it is located in a protected and sufficiently sealed area. Very high demands are already placed on the sealing of plug connections in measuring devices in process and automation technology, so the adjusting screw can be installed with little effort in terms of its own sealing.

[0014] A further advantage of the inventive solution is the protection against unintentional actuation during operation. When the mating connector is plugged in, the adjusting screw is located in a closed and protected area, so that actuation is only possible by disconnecting the connector and thus interrupting the power supply.

[0015] Because the adjustment screw is operated with a simple screwdriver and therefore without special tools or other accessories, the invention is simple and universally applicable.

[0016] Advantageously, the standardized connector is designed with four contact pins evenly distributed around the longitudinal axis, particularly in accordance with DIN EN 61076 in the M12 or M8 design. Such connectors or plug-in connections have been used in process and automation technology for many years. It is particularly advantageous to position the adjusting screw in the connector centrally between the contact pins.

[0017] A particularly advantageous embodiment provides that the measuring device comprises an internal energy storage unit and a display unit, and that the energy storage unit supplies power to the display at least temporarily. This makes it possible for the parameter change made via the adjustment screw to be readable at least temporarily.

[0018] The invention is explained in more detail below using exemplary embodiments with reference to the drawings.

[0019] They show schematically: Fig. 1 a measuring device for process and automation technology, Fig. 2 a cross-sectional view through the connector and housing of the measuring device Fig. 1 and Fig. 3 a top view of the connector of the measuring device.

[0020] In the following description of the preferred embodiments, like reference numerals designate like or comparable components.

[0021] In Fig. 1 shows a typical measuring device 1 for process and automation technology, for example in the form of a pressure measuring device. A housing 2 is placed on a process connection 4. The measuring device 1 is connected via the process connection 4 to a container containing the medium to be measured, i.e. a pipeline, a tank or the like. This connection is usually made by means of a flange formed onto the container or a corresponding adapter. A plug connection 3 is arranged at the top of the housing 2, via which the pressure measuring device 1 is supplied with power and which acts as an electronic interface and makes the generated measurement signals available for further processing by the aforementioned control unit, e.g. a PLC. A typical design of the plug connector according to DIN EN 61076 in the M12 design is shown.

[0022] Shown in Fig. 1 a so-called transmitter device that does not have any display or control unit. Apart from that, there are also measuring devices 1 whose housing 2 has a display and control unit mounted on it, which displays the measurement results and allows various settings to be made by the operating personnel, such as setting a switching point or displaying the measured values ​​in different units of measurement.

[0023] Since transmitter devices according to Fig. 1 no input options are provided, either only the output of an analog signal is possible or the input of parameters must be made via a connected control unit.

[0024] According to the invention, an input possibility in the form of an adjusting screw 20 is therefore provided within the plug connection or plug connector 3, as shown in Fig. 2. The above-mentioned embodiment of the standardized connector comprises four contact pins 3a, of which Fig. 2 two are shown. The adjusting screw 20 is arranged centrally between the contact pins 3a and parallel to their longitudinal direction, as Fig. 3. It is both rotatable and movable longitudinally. It is operated using a screwdriver placed in the slot indicated on the screw head.

[0025] Inside the measuring device is an electronic unit 10, which includes means for conditioning, amplifying, and processing the acquired measurement signals. One part of this is a potentiometer 11, which Fig.2 is shown as an example in the form of a small box. Using this potentiometer 11, a parameter such as a switching point, a hysteresis value, or a limit value can be easily set. It is also interesting, for example, with level measuring devices to easily set the type of medium to be measured, e.g., water or oil, given the different dielectric constants. This example clearly shows that there is a need to be able to make simple "high-low" settings.

[0026] The potentiometer 11 is influenced by the rotary movement generated by the screwdriver, which is transmitted to the potentiometer 11 via the adjusting screw 20. The longitudinal mobility of the adjusting screw 20 also provides another input option, for example, to confirm the values ​​set by the rotary movement.

[0027] In the transmitter measuring device shown, the set value can be displayed, for example, on a scale or acoustically or haptically in the form of a clicking sound during the rotational movement. However, the invention is equally suitable for measuring devices that have their own display unit, since the set parameters can be read directly on the display. For this purpose, it is advisable for the measuring device 1 to include an internal energy storage device (not shown in detail here), and for this energy storage device to power the display at least temporarily. This makes it possible for the parameter change made via the adjusting screw 20 to be readable at least temporarily. However, all embodiments have the advantage that the provision of setting options on the housing 2 of the measuring device 1, which would require additional device openings, could be eliminated.

Claims

[1] Measuring device for process and automation technology for detecting a physical quantity, with a sensor element, an electronic unit (10) and a signal output (3), wherein the electronic unit (10) is arranged in a housing (2) and serves to evaluate and / or process the measurement signals generated by the sensor element, and wherein the signal output (3) is designed as a standardized connector (3) with contact pins (3a) projecting from the housing (2), via which the measuring device (1) is supplied with energy and the generated measuring signals can be tapped off by a higher-level control unit, wherein the connector (3) comprises an adjusting screw (20) for influencing the electronic unit (10), which is arranged parallel to the longitudinal direction of the contact pins (3a) and can be operated by means of a screwdriver, wherein the adjusting screw (20) is displaceable in the longitudinal direction, wherein the adjusting screw (20) is rotatable about its axis and wherein the electronic unit (10) comprises a potentiometer (11) and the adjusting screw (20) influences this potentiometer (11) by rotational and / or longitudinal movement. [2] Measuring device according to claim 1, characterized by that the standardized connector (3) is designed with four contact pins (3a) distributed circumferentially evenly around the longitudinal axis. [3] Measuring device according to claim 1 or 2, characterized by that the adjusting screw (20) in the connector (3) is arranged centrally between the contact pins (3a). [4] Measuring device according to one of the preceding claims, characterized by that the connector (3) is designed in accordance with DIN EN 61076 in the M12 or M8 design. [5] Measuring device according to one of the preceding claims, characterized bythat an internal energy storage device and a display unit are present and the energy storage device supplies the display with current at least temporarily so that the parameter change made via the adjusting screw (20) can be read.

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