DEVICE, SENSOR UNIT AND TRANSMITTER FOR DETERMINING A MEASURED VARIABLE

Abstract

A device (1) for determining a measured variable, that allows an as simple as possible adaptation to the measurement conditions, is achieved in that the device (1) has a sensor unit (2) and a transmitter (3). The sensor unit (2) generates an electric primary signal in dependence on the measured variable, and communicates the primary signal via an analog output interface (4) to the transmitter (3) which processes the primary signal. Furthermore, the sensor unit (2) and transmitter (3) are advantageous by themselves, and the sensor unit (2) preferably allows for offline calibration under constant surrounding conditions.

Claims

1-13. (canceled)

14. A device for determining at least one measured variable, comprising: at least one sensor unit and at least one transmitter, wherein the sensor unit generates at least one electric primary signal in dependence on a measured variable and is configured to communicate the primary signal via an analog output interface to the transmitter, and wherein the transmitter is adapted for processing the primary signal.

15. The device according to claim 14, wherein the sensor unit and the transmitter are detachably connectable to one another.

16. The device according to claim 14, wherein at least one electronic insert is assigned to the sensor unit, wherein the electronic insert has at least one analog input interface, wherein the electronic insert is adapted for processing at least the primary signal based on the measured variable and wherein the electronic insert and the transmitter are detachably connectable to one another.

17. The device according to claim 14, wherein the sensor is a pH sensor.

18. a sensor unit for determining at least one measured variable, comprising: at least one sensor and an analog output interface, wherein the sensor unit is adapted for generating at least one electric primary signal in dependence on the measured variable and for generating emiting the electric primary signal via the analog output interface.

19. The sensor unit according to claim 18, wherein the at least one sensor comprises a pH sensor.

20. The sensor unit according to claim 19, wherein the sensor unit is calibrateable offline under definable conditions.

21. The sensor unit according to claim 15, wherein the sensor unit has at least one data carrier, wherein data assigned to the sensor unit is storable in the data carrier and wherein the data carrier is arranged on and/or in a housing of the sensor unit.

22. The sensor unit according to claim 21 wherein the data carrier is an RFID or NFC tag.

23. The sensor unit according to claim 15, wherein the sensor unit the analog output interface is the sole output interface and wherein the sensor unit is free of elements that generate a digital signal from the primary signal and/or a determine a value of the measured variable from the primary signal.

24. The sensor unit according to claim 23, wherein the sensor unit is free of electronic components.

25. A transmitter for processing primary signals of at least one sensor unit, comprising: at least one electronics receptacle for an electronic insert adapted for detachably receiving the at least one sensor unit and for processing the primary signals thereof.

26. The transmitter according to claim 25, wherein at least one data reader is provided for reading data from a data carrier of the at least one sensor unit.

27. The transmitter according to claim 25, wherein the data reader is adapted for writing data on the data carrier of the at least one sensor unit.

28. The transmitter according to 25, further comprising at least one radio interface.

29. The transmitter according to claim 25, further comprising at least one input/output interface.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0051] The sole FIGURE is a purely schematically depicted measurement arrangement.

DETAILED DESCRIPTION OF THE INVENTION

[0052] A part of a device 1 for determining a measured variable is shown in FIG. 1. A sensor unit 2 carries out the actual measurement and generates a primary signal. The primary signal, which has a known dependence on the measured variable, is communicated to a transmitter 3 and processed by the transmitter. The processing relates, for example, to a treatment, e.g., a conversion into a 4 . . . 20 mA signal or to a determination of the measured value of the measured variable.

[0053] Thereby, the transmitter 3 is variably designed so that it can convert a plurality of different measured signals into many different output signals. This is, thereby—as shown—possible in the process, but also in a laboratory, i.e. under definable surrounding conditions.

[0054] The sensor unit 2 has, overall, two analog output interfaces 4, via which only analog signals are output. In the illustrated example, there are two wires that transfer an electric voltage. The sensor unit 2 is connected to an electronic insert 5 that is assigned to it or, respectively, assigned to the measuring principle of the respective sensor unit 2. Thus, different sensor units 2 can be connected to an electronic insert 5, insofar as the sensor units 2 are used for determining the same measured variables with the same measuring principle. For the reception of the analog primary signal, the electronic insert 5 has an analog input interface 6.

[0055] The electronic insert 5 is tailored to the sensor unit 2 in the respect that it contains components that allow for the determination of the value of the measured variable from the primary signal. Preferably, suitable evaluation algorithms are also stored.

[0056] If it is necessary, depending on the measuring method, that the sensor unit 2 is calibrated or special material data of the sensor unit 2 is required for determining the measured variable, then this data is stored on a data carrier 7, which the sensor unit 2 provides.

[0057] In one variation, only one identification of the sensor unit 2 is stored, from which, if necessary, the necessary information for the determination of the measured variable can be provided by means of accessing externally stored data.

[0058] In this case, the data carrier 7 is mounted in the housing 8 that forms the sensor unit 2.

[0059] In order to implement the measurements of different measured variables using a transmitter 3, two electronic receptacles 9 are provided here. The electronic insert 5 is located in one of them. The other is shown as being free of the second electronic insert 5′ of the second sensor unit 2′ indicated here as fill level meter, but would be inserted for use.

[0060] Based on the data of the data carrier 7, the sensor unit 2 can be automatically identified, since the transmitter 3 has a data reader 10. If the data carrier 7 is a bar code, then the data reader 10 is a bar code scanner. If the data carrier 7 is a NFC tag, as is the case here, then the data reader 10 accordingly reads the data.

[0061] A radio interface 11 is provided in order to be able to access the data for sensor units that have no or little data on their data carrier 7, via which access to an external database 12 is available for the transmitter 3.

[0062] The sensor unit 2 connected to the transmitter 3 here—or, more exactly, via the electronic insert 5 inserted in the electronics receptacle—is used for measuring pH. A measuring electrode 13 and a reference electrode 14 are provided for this. The measuring electrode 13 is located in a glass body that closes with a glass membrane. The housing 3 of the sensor unit 2 is limited on one side by a diaphragm 16. Additionally, a temperature sensor is also provided. An electric contact can also be attached to this temperature sensor, so that the temperature signal can also be used for determining the pH value. This is not shown here for reasons of clarity.

[0063] Both electrodes 13, 14 are each directly attached via a wire 17 to the analog input interface 6 of the electronic insert 5. The analog input interface 4 is, hereby, simply two electric terminal contacts. Alternatively, the sensor unit 2 and the electronic insert 5 are connected to one another via a—not shown—multi-pole cable.

[0064] The electronic insert 5 determines a measure for the pH value from the arising electric potentials, in each case, by using calibration data.

[0065] Preferably, a uniform format is used for the output signal of the electronic insert 5, 5′, so that the transmitter 3 is always able to deal with these signals in the same manner.

[0066] For further data processing, the transmitter 3 has its own data storage 18, on which additional data for different sensor units 2 or for electronic inserts 5 can be stored.

[0067] The second electronic insert 5′ has a storage unit 19, in which the data can be stored using a plurality of different sensor units 2 or second sensor units 2′.

[0068] If the measurement data is suitably processed or treated, then it is communicated by the transmitter 3 via its field bus interface 20 and a field bus 21 to a—not shown here—control room.

[0069] Control of the transmitter 3 or, respectively thereby, of the measurements by means of the sensor units 2, 2′ is carried out by a user 22 utilizing a tablet 23.