DE102012112917A1 - Process automation device e.g. coriolis volumetric flow meter, for analysis or inspection of flow of medium in container, has energy production unit formed as integral part of transmitter housing and/or sensor housing - Google Patents

Abstract

The device (1) has a control/evaluation unit (5) comprising a sensor element (4) for determining a process measured variable of a medium (3) and outputting a measured value of the process measured variable. An energy production unit (14) partially supplies energy required for an operation of the control/evaluation unit and an operation of the sensor element. The energy production unit is formed as an integral part of a transmitter housing (7) and/or a sensor housing (18). The energy production unit is integrated in a housing wall of the transmitter and/or sensor housings. The transmitter housing is designed as a synthetic transmitter housing (7a). The sensor housing is designed as a synthetic sensor housing (18a). The energy production unit is designed as a solar cell (2) i.e. transparent solar cell (2a), a thermoelectric converter element, a piezoelectric element and/or an inductive converter element. The sensor element is designed as an analyzer.

Description

The present invention relates to an apparatus for process automation technology for determining or monitoring at least one physical, biological or chemical process variable of a medium, comprising at least one sensor element, at least one control / evaluation unit which determines the process variable determined by the sensor element and at least one Output measured value of the process variable and at least one power generation unit which at least partially supplies the control / evaluation unit and at least partially the sensor element with the energy required for operation.

In automation technology, in particular in process automation technology, measuring devices or field devices are often used which serve to detect and / or influence process variables. Sensors that are used, for example, in level gauges, flowmeters, pressure and temperature measuring devices, pH redox potential measuring devices, conductivity meters, etc., which contain the corresponding process variables level, flow, pressure, temperature, pH or conductivity, are used to record process variables to capture. To influence process variables are actuators, such as valves or pumps, via which the flow of a liquid in a pipe section or the level in a container can be changed. In principle, field devices are all devices that are used close to the process in the process plant and that supply or process process-relevant information. In the context of the invention, field devices are thus also understood as remote I / Os, radio adapters or generally electronic components which are arranged on the field level. A variety of such field devices is manufactured and sold by the company Endress + Hauser.

• • Durchflussmessgeräte sind insbesondere Coriolis-, Ultraschall-, Vortex-, thermischen und/oder magnetisch induktiven Durchflussmessgeräte.
• • Füllstandsmessgeräte sind insbesondere Mikrowellen-Füllstandsmessgeräte, Ultraschall-Füllstandsmessgeräte, zeitbereichsreflektometrische Füllstandsmessgeräte (TDR), radiometrische Füllstandsmessgeräte, kapazitive Füllstandsmessgeräte, induktive Füllstandsmessgeräte und/oder temperatursensitive Füllstandsmessgeräte.
• • Druckmessgeräte sind insbesondere Absolut-, Relativ- oder Differenzdruckgeräte.
• • Temperaturmessgeräte sind insbesondere Messgeräte mit Thermoelementen und temperaturabhängigen Widerständen.
• • Grenzstandsmessgeräte sind insbesondere Ultraschall-Grenzstandsmessgeräte und/oder kapazitive Grenzstandsmessgeräte.
• • Analysemessgeräte sind insbesondere pH-Sensoren, Leitfähigkeitssensoren, Sauerstoff- und Aktivsauerstoffsensoren, (spektro)-photometrische Sensoren, und/oder ionenselektive Elektroden.

A field device is in particular selected from a group consisting of flowmeters, level gauges, pressure gauges, temperature measuring device, point level measuring devices and / or analysis measuring devices.

• • Flowmeters are especially Coriolis, ultrasonic, vortex, thermal and / or magnetic inductive flowmeters.
• • Level gauges are in particular microwave level gauges, ultrasonic level gauges, time domain reflectometric level gauges (TDR), radiometric level gauges, capacitive level gauges, inductive level gauges and / or temperature sensitive level gauges.
• • Pressure gauges are in particular absolute, relative or differential pressure devices.
• • Temperature measuring devices are in particular measuring devices with thermocouples and temperature-dependent resistors.
• • Point level measuring devices are in particular ultrasonic point level measuring devices and / or capacitive point level measuring devices.
• • Analytical instruments are in particular pH sensors, conductivity sensors, oxygen and active oxygen sensors, (spectro) -photometric sensors, and / or ion-selective electrodes.

For example, the level or level of a medium in a container with vibronic measuring devices, which detect the difference of the vibrations of a vibration system with covered and freely oscillating vibration system, or with capacitive probes, the change in capacitance of a metal probe and the container wall formed capacitor at different degrees of coverage with medium detect, be determined. The evaluation of the vibrations or the capacity is carried out electronically in a control / evaluation unit, which is usually arranged together with other electronics. The electronics must be supplied with power, which is usually done via two-wire or four-wire technology. With a large number of measuring devices, the direct wiring of these measuring devices is very complicated and cost-intensive.

Furthermore, for example, in chemical, biotechnological, pharmaceutical and food processing processes, and in environmental metrology and automatic analyzers, so-called analyzers for determining a measurement of a liquid sample are used. To a certain extent, analyzers can be used to monitor and optimize the purification performance of a wastewater treatment plant, to monitor drinking water or to monitor the quality of food. For example, the content of the liquid sample in a specific substance, which is also referred to as analyte, is measured and monitored. For example, analytes may include ions such as ammonium, phosphate, silicate or nitrate, biological or biochemical compounds, e.g. As hormones, or microorganisms. Other parameters that are determined by analytical instruments in process measurement, especially in the field of monitoring of water, are the total content of organic carbon (TOC) or the chemical oxygen demand (COD). Analysis devices can be configured, for example, as cabinet devices or as buoys.

Often, in analyzers, the sample to be analyzed is treated by adding one or more reagents so that a chemical reaction occurs in the liquid sample. Preferably, the reagents are so chosen that the chemical reaction by means of physical methods, for example by optical measurements, by means of potentiometric or amperometric sensors or by a conductivity measurement is detectable. For example, the chemical reaction may cause a coloration or a color change that is detectable by optical means. The color intensity in this case is a measure of the measured variable to be determined. The measured variable can be determined, for example, photometrically by irradiating electromagnetic radiation, for example visible light, from a radiation source into the liquid sample and, after transmission through the liquid sample, being received by a suitable receiver. The receiver generates a measurement signal which is dependent on the intensity of the received radiation and from which the measured quantity can be derived.

In order to use such analysis methods automatically, for example in the industrial sector or for monitoring a sewage treatment plant or a body of water in the open air, it is desirable to provide an analysis device that automatically performs the required analysis methods. The most important requirements for such an analyzer, as with most other field devices of industrial process automation technology, are robustness, independent power supply, energy self-sufficiency, ease of use, and sufficient working or environmental safety, in addition to adequate measurement accuracy.

Automatic analyzers are already known from the prior art. For example, show DE 102 22 822 A1 . DE 102 27 032 A1 and DE 10 2009 029 305 A1 Online analyzers for analyzing samples.

In field devices of industrial process automation technology, the respective device electronics is usually housed in a relatively robust, such as impact, pressure, explosion and / or weatherproof, electronics housing. This can be located away from the device and connected to this only via a flexible line; but it can also be arranged directly on the sensor or a measuring transducer housing einhausenden separate sensor housing. Examples of such, suitable for field devices electronics housing are among others the US 63 66 436 B2 , of the DE 101 26 654 A1 , of the DE 10 2008 042 972 A1 , of the US 65 56 447 B2 or the WO 98/14763 A1 refer to. Accordingly, such electronics housing each comprise one or more cavities having, usually cup-shaped housing body with a side limiting its cavity, usually partially circular cylindrical side wall, with an open end and with a cavity on the open end opposite and away from it delimiting, for example, flat or curved outwards, possibly also detachable, rear wall and a housing with the housing body at its open end, for example by means of screw, releasably connected and this closing housing cover. The usually also an integrated therein - for example, the viewing of a placed behind the housing base body display element enabling - viewing window having housing cover is usually bolted to the housing body, for example in the manner of a screw cap. Namely viewing window, sight glass or sight glass is usually formed by means of a translucent or transparent material, such as glass, glass ceramic or plastic, existing, usually window pane which covers a provided in a mostly metallic or at least metallized cover body opening window opening.

Industrial-grade electronic devices, thus also their respective electronics housing and their respective housed electronics, must be known to meet very high protection requirements, esp. With regard to the foreclosure of the electrical components placed therein against external environmental influences, in terms of protection against any contact with live components and / or with regard to the prevention of electrical sparks in the event of a fault. This includes, for example, the requirement that an electric current that could flow, for example in the case of a physical connection, via electronics housing to ground or earth, must not exceed a maximum permissible maximum value. For example, if the electrical device is connected to 250 V, this maximum permissible value is 10 mA. If these requirements are met, the device meets at least the requirements of protection class 11, ie it is an electrical device with protective insulation. To realize these requirements, it is therefore necessary that the housing of the electrical device is sufficiently isolated from all live parts of the device. Such insulation is particularly necessary if it is a housing made of electrically conductive material, such as a metal. In addition, electronics housing, thus the device electronics placed therein, against penetration of moisture or foreign substances / body, esp. Dust, as well as from external contact to a sufficient extent to protect. The on the part of the respective electronics housing, not least also given the application and environmental conditions, to be met protection against ingress, such as by contact, foreign bodies or water, for example, based on in the German standards DIN EN 60529 respectively. DIN 40 050 defined protection types, z. B. "dust-proof or all-round splash water (IP54)" or "dust-proof or permanent immersion (IP68)", or classes or according to Industry standard NEMA 250 determinable.

In addition, electronic devices, including field devices that are to be operated in potentially explosive areas, must also meet very high safety requirements with regard to explosion protection. In this context, different types of protection are distinguished in explosion protection, which are also manifested in accordance with relevant standards and standards in relevant electrical equipment for hazardous areas, such. Tie European standards EN 60079-xx , the US standards FM36xx , of the Canadian standard C22.2 , of the International standard IEC 60079-18 or the Standards DIN EN 50 014 ff ,

When using the field devices or the measuring devices in extensive outdoor facilities, such as pipelines, the external power supply of the measuring device via cables is difficult, since cables of enormous length would have to be laid over long distances. That's why batteries are used here. The disadvantage here, however, is that they only have a finite life and must be replaced. From the Scriptures WO 2008/006463 A1 In addition, a measuring device is known which has a solar module integrated in the housing. With the help of the solar module, power can be generated directly at the location of the measuring device and ensure the self-sufficient power supply of the measuring device for many years.

The object of the invention is to provide a field device or measuring device of the process automation for determining a physical, biological or chemical process variable, which is supplied with energy autonomously and meets the safety requirements.

The object is achieved by a device of process automation for determining or monitoring at least one physical, biological or chemical process variable of a medium, according to the features of claim 1.

According to the invention, the process automation device is used for determining or monitoring at least one physical, biological or chemical process variable of a medium and consists at least of a sensor element, a control / evaluation unit, and a power generation unit. Whereby the process variable is in particular the fill level, the density, the viscosity, the temperature, the pH, the substance content of a particular substance, the pressure, the humidity or the flow of the medium. The control / evaluation unit determines the measured process variable with the sensor element and outputs this process variable as a measured value. The power generation unit supplies at least partially the control / evaluation unit and the sensor element with energy that is necessary for their operation. This is preferably configured as a self-sufficient energy supply unit which operates according to the principle of so-called energy harvesting and which, for example, obtains the energy required for operating the measuring device, for example from the ambient temperature, from vibrations or from air currents.

• – der Photovoltaik, zur Umsetzung der elektromagnetischen Strahlungsenergie,
• – der Piezoelektrizität, zur Umwandlung der mechanischen, statischen oder dynamischen Spannungen im Material,
• – der Elektromagnetische Generatoren zur Umsetzung der Bewegung, Vibrationen und/oder Luft-/Wasserströmungen,
• – der Pyroelektrische oder Thermoelektrische Generatoren, zur Umsetzung einer Temperaturänderung in eine Ladungstrennung und/oder Elektronenfluss im Material, oder
• – Antennen, zur Umwandlung der elektromagnetischen Strahlungsenergie aus der Umgebung, in elektrische Energie verwendet

There are several options according to the principle of so-called. Energy Harvesting the energy-harvesting kinetic, chemical or potential energy forms, such. As heat, light radiation, vibration, vibrations, etc. to convert into an electrical energy form. There are, for example, the conversion options:

• - photovoltaics, for the implementation of electromagnetic radiation energy,
• - the piezoelectricity, to convert the mechanical, static or dynamic stresses in the material,
• - the electromagnetic generators to implement the movement, vibrations and / or air / water flows,
• - The pyroelectric or thermoelectric generators, to implement a change in temperature in a charge separation and / or electron flow in the material, or
• - Antennas, used to convert the electromagnetic radiation energy from the environment, into electrical energy

The energy generating unit is designed as an integral component of a transmitter housing which surrounds at least the control / evaluation unit and / or a sensor housing which surrounds at least the sensor element. In addition, for example, the power generation unit is integrated into the housing wall of the transmitter housing and / or the sensor housing by, for example, the power generation unit by means of an injection molding hermetically sealed and the protection of measuring devices in potentially explosive atmospheres sufficient in the housing wall of a plastic transmitter housing and / or the plastic sensor housing injected. The integration of the power generation unit in the transmitter or sensor housing has the advantage that, for example, by the introduction of the power generator unit in the housing wall of the transmitter or sensor housing as a supporting structural part, the requirements of the housing static, the pressure resistance of the housing, the tightness, the dielectric strength and the explosion protection are completely fulfilled. Furthermore, the integration of the power generation unit in the container wall of the transmitter housing or the sensor housing also has the advantage that the safety requirements for the meter can be achieved despite the more compact design of the meter by means of integration.

According to the invention, the power generation unit supplies the entire device at least partially with the energy required for operation and is for this purpose, for example via an electrical line or a wireless, z. B. inductive, energy transmission path connected to a power supply unit located in the transmitter housing. This power supply unit controls the energy consumption and the power supply of the device and optionally stores the energy generated by the power generation unit, but which is not currently required, in an energy storage unit. The energy storage unit is designed so that only so much energy can be cached that it still meets the previously described, high safety requirements in terms of explosion protection. The energy storage unit is an accumulator, condenser, fuel cell or reversible reduction-oxidation flux battery, which converts electrical energy into a chemical compound of the reaction elements contained in a solvent. The energy storage unit ensures that the meter is sufficiently supplied with energy even at night or in the event of insufficient energy supply by the power generation unit.

In order to generate the energy necessary for supplying the device or the field device, the integral energy generating unit is designed, for example, as at least one solar cell, at least one thermoelectric transducer element, at least one piezoelectric element and / or at least one inductive transducer element. The energy generating unit integrated in the transmitter housing or sensor housing enables the generation of a certain amount of electrical energy from the ambient variables, such as the ambient temperature, the mechanical vibrations or the vibrations on the measuring instrument, medium flows through the measuring instrument or light irradiation onto the measuring instrument. To obtain the energy from the surroundings of the measuring device, for example, piezoelectric crystals which generate electrical voltages due to the action of force, solar cells which generate electrical energy from the ambient light, thermoelectric generators or pyroelectric crystals, which required from existing temperature differences between two separate areas, gain electrical energy, and antennas that absorb the electromagnetic radiation from the environment used.

As an energy generating unit, for example piezoelectric crystal element with resilient elements of the construction of the transmitter housing and / or the sensor housing are connected vibration mechanical, d. H. the mechanical vibrations, which act on the transmitter housing and / or the sensor housing due to vibrations and vibrations, are transmitted directly or mechanically amplified to the piezoelectric element via these resilient elements. The energy conversion of the mechanical vibration energy into electrical energy occurs through the piezoelectric effect. The direct piezoelectric effect converts a mechanical pressure on a piezoelectric crystal element into an electrical voltage. In the field of energy self-sufficient field devices such piezoelectric elements can generate the energy required for the measurement process and for a possible signal transmission to a remote control center, in which they convert existing mechanical vibration energy in the environment into electrical energy. This piezoelectric element can also be integrated directly into the housing wall of the transmitter housing and / or the sensor housing by an injection molding process or enclosed completely and sealed by the material of the housing wall of the transmitter housing and / or the sensor housing. These piezoelectric elements are aligned with their piezoelectrically active crystal direction in the housing wall in such a way that the mechanical stresses resulting from external force or mechanical vibrations are absorbed in the housing wall of the transmitter housing and / or the sensor housing and converted into electrical energy.

The energy supply unit can also be designed as a Peltier element or thermoelectric converter element, which enables an energy conversion of thermal energy into electrical energy by means of the thermoelectric effect. When Peltier element at least two conductors with different electronic heat capacities are brought into contact and by means of temperature differences on the two conductors, an electric electron current is effected. This effect is also reversible, so that by the Peltier element, by means of an electrical current fed into the conductor, a temperature difference at the two conductors, for example for cooling, is generated.

A disadvantage of the thermoelectric generators is the very low efficiency of less than 10%. However, the advantages of thermoelectric generators are that these are almost are maintenance-free, since there are no moving parts and the naturally occurring temperature differences between two separate areas, such as temperature differences on the outer wall and the inner wall of the transmitter housing, can be used.

When using the photoelectric effect in photovoltaics, light energy is made directly usable by the solar cell for electrical consumers. These solar cells may be applied as a coating directly on at least one outer surface of the transmitter housing. The advantages of the direct coating of partial elements of the measuring device compared to a separate attachment of a solar module are that on the one hand, the solar cells are an integral part of the meter and therefore are very stable, and on the other hand, the solar cells forming coating simultaneously provides corrosion protection of the housing. The anyway necessary coating of the housing with a weather-resistant material is replaced by the coating with the solar cells forming materials. The coating of the solar cell is applied as a foil or as a dye solar cell on the transmitter housing. The multilayer coating is essentially composed of electrode, counter electrode, catalyst, electrolyte and dye, which together form a dye solar cell (Grätzel cell). The basis of the dye solar cell forms the dye contained therein, which converts photons from solar radiation into free charge carriers. Such dyes are z. B. marketed by the company Dyesol. Among other things from the writing WO 2009/033214 A1 is a method for producing the novel dye solar cells known. Compared to conventional silicon solar cells dye solar cells are cheaper to produce, since the required materials are cheaper.

Furthermore, the power generation unit, for. B. formed as a solar cell made of an at least partially transparent material, directly as a sight glass on a display integrated in the meter display / control unit.

The invention will be explained in more detail with reference to the following figures. It shows:

1 a point level measuring device with a solar cell according to the invention integrated in the transmitter housing as an energy supply unit;

2 an analysis measuring device with a thermoelectric converter according to the invention integrated in the transmitter housing as a power supply unit;

3 a flow meter with an inventive integrated in the sensor housing piezoelectric transducer as an energy supply unit.

In 1 is a measuring device 1 for determining the limit level of a medium 3 represented in a container or a pipeline. The measuring device shown here 1 for limit level measurement comprises a sensor element 4 which based on a vibronic measuring principle based on the level or level of the medium 3 determined in the container or in the pipeline. That meter 1 has a sensor element projecting into the container 4 with a sensor housing 18 . 18a and outside the container located transmitter housing 7 . 7a in which, for example, a control / evaluation unit 5 , a power supply unit 6 and an energy storage unit 19 are located. The measuring device 1 is by means of a at the joint of the sensor housing 18 . 18a and the transmitter housing 7 . 7a provided thread attached to a container or a pipe. In this embodiment, the transmitter is exposed to the sun radiation 7 . 7a of the meter 1 a solar cell 2 . 2a as an energy production unit 14 integrated, which converts the radiant energy into electrical energy and the power supply unit 6 at least for partial supply of the measuring device 1 with the energy needed. The solar cell 2 . 2a can as a coating 11 in multiple layers of different materials such on the transmitter housing 7 . 7a be applied so that one or more dye solar cells 13 form. The layers are applied using methods of thin-film technology or solar cell production known to those skilled in the art and will not be described in more detail here. A process for the preparation of dye-containing solar cells is for example in the document WO 2009/033214 A1 described. Furthermore, the solar cells 2 . 2a the sight glass above the display / control unit 10 or be integrated into them by partially transparent or transparent solar cells 2a be used, which is the view on the display of the display / control unit 10 enable. The solar cell 2 Can also be used as a foil 12 or dye solar cells 13 forming coating 11 directly on the outer surface 9 of the sensor housing 18 . 18a and the transmitter housing 7 . 7a form and thus directly in the housing walls 8th be integrated. In this embodiment of the sensor housing 18 . 18a and the transmitter housing 7 . 7a becomes the power generation unit 14 , in particular the solar cell 2 . 2a integrated directly into the layer composite material or laminates of the different layers. In the case of the layered composite material, at least two or more laminar layers of the same or different materials are bonded together. Becomes a solar cell 2 . 2a in a housing wall 8th one sensor housing 18 . 18a and / or a transmitter housing 7 . 7a glued into the composite material, so at least partially transparent layer to cover the active side of the solar cell use, so that the incident light to the solar cell 2 . 2a can get.

Through one in the transmitter housing 7 . 7a integrated energy storage unit 19 is it possible for the meter 1 Also at night or in low sunlight with the required energy can be supplied. The power supply unit 6 regulates the power supply of the measuring device 1 by with good energy through the external environmental factors, eg. B: Sunlight, on the solar cell 2 . 2a as an energy production unit 14 the operation of the meter 1 excess energy in the energy storage unit 19 is stored between. If the power generation falls below a predetermined limit, which is to supply the meter 1 is absolutely necessary, so engages the power supply unit 6 on in this energy storage unit 19 stored energy back.

When designing the meter 1 , in particular the energy storage unit 19 and the power supply unit 14 make sure that they meet the very high safety requirements with regard to explosion protection. In particular, it is important to avoid the formation of sparks, or at least to ensure that any spark generated inside a confined space has no effect on the environment, so as to reliably prevent the potentially possible triggering of an explosion. As for example in the US-B 63 66 436 or the US-B 65 56 447 this or previously stated, different types of protection are distinguished in connection with explosion protection, which are also manifested in accordance with relevant standards and standards in relevant electrical equipment for hazardous areas, such. Tie European standards EN 60079-xx , the US standards FM36xx , of the Canadian standard C22.2 , of the International standard IEC 60079-18 or the Standards DIN EN 50 014 ff , So z. B. according to the European standard EN 60079-11: 2007 Explosion protection given when electronic gauges 1 are formed according to the type of protection defined therein or protection class with the name "intrinsic safety" (Ex-i). According to this protection class, the values for the electrical quantities have current, voltage and power in an electronic measuring device 1 each time below a given limit to lie. The three limits are chosen so that in case of error, z. B. by a short circuit, the maximum amount of heat is insufficient to generate a spark. The current is z. B. by resistors, the voltage z. B. by zener diodes and the power by appropriate combination of current and voltage-limiting components below the specified limits. In the European standard EN 60079-7: 2007 Another class of protection is named "Increased Safety" (Ex-e). For electronic measuring devices 1 , which are designed according to this class of protection, the ignition or explosion protection is achieved in that the spatial distances between two different electrical potentials are so large that a spark can not occur even in case of error due to the distance. However, under certain circumstances, this can mean that circuit arrangements must have very large dimensions in order to meet these requirements. As another protection class is in the European standard EN 60079-1: 2007 Furthermore, the type of protection "Flameproof Enclosure" (Ex-d) is listed. For this purpose, electronic measuring devices or field devices must 1 which are designed according to this class of protection must have a pressure-resistant transmitter housing 7 . 7a and / or sensor housing 18 . 18a by which it is ensured that one inside this housing 7 . 7a . 18 . 18a occurring explosion can not be transferred to the outside space. Pressure-resistant housing 7 . 7a . 18 . 18a are, so they have sufficient mechanical strength, formed comparatively thick-walled. According to the invention are in these thick housing walls 8th of the transmitter housing 7 . 7a or sensor housing 18 . 18a as static and / or reinforcing construction elements, the energy supply units 14 integrated. These power supply units 14 can at a plastic transmitter housing 7a and / or plastic sensor housing 18a for example, by means of an injection molding process directly from the plastic material of the plastic transmitter housing 7a or plastic sensor housing 18a be enclosed and thus sealed, pressure-tight encapsulated. A corresponding standard for Vergusskapselung (Ex-m) is for example in the EN 60079-18: 2004 manifests. This is a type of protection in which components and / or assemblies of the electronic device, which could potentially ignite an explosive atmosphere by sparks or by heating, are encapsulated in a mostly elastomers and / or foamed plastic investment that contact with the explosive atmosphere largely excluded and so inflammation can be prevented. In the USA, in Canada, in Japan and other countries there are with the aforementioned European standards comparable standards, such as FM3600, FM3610 or C22.2 no. 157 Etc..

2 discloses a measuring device 1 for the analysis of the substance concentration and / or material properties in a medium 3 , For this purpose, the sensor element 4 depending on the measured variable to be determined as Analyzer, pH sensor, conductivity sensor, oxygen and active oxygen sensor, spectrometric sensor, and / or ion-selective electrode formed. The individual measuring methods will not be discussed further in this application.

The power generation unit 14 is in this embodiment in the transmitter housing 7 . 7a as a thermoelectric transducer element 15 , which determines the temperature difference of the outer surface 9 the housing wall 8th integrated into the interior for generating energy. The temperature difference is in this case for example by a heat radiation θ, at least the outer surface 9 of the transmitter housing 7 . 7a correspond heated or cooling the same.

An electrothermal transducer, in particular a Peltier element, uses the movement of charge carriers within a temperature gradient to convert this thermal energy into electrical energy. Additionally or alternatively, the power generation unit 14 also as a piezoelectric transducer element 16 or inductive transducer element 17 be configured, which on the transmitter housing 7 . 7a of the meter 1 acting mechanical vibration energy converts into electrical energy. For this purpose, on the transmitter housing 7 . 7a additionally be designed swingable spring elements that this vibration energy directly or amplified on the piezoelectric transducer element 16 or the inductive transducer element 17 transfer.

In 3 is shown a Coriolis flowmeter of the applicant. This meter 1 is an example of a measuring device 1 in which the power generation unit 14 also directly in the sensor housing 18 . 18a can be integrated. It is also possible, only the pipe element sensitive to the measurement 41 with the coating 2 to provide. Similar to the Coriolis flowmeter shown here, the sensor housing 18 . 18a electromagnetic flowmeters or vortex-based flowmeters or the horn antennas of radar level gauges, etc., with the power unit of the present invention integrated into the housing material 14 be designed.

This embodiment of the power generation unit 14 in the sensor housing 18 . 18a has the advantage that the vibration energy and heat energy from the process or the medium 3 can be better exploited.

LIST OF REFERENCE NUMBERS

1

Device, measuring device, field device

2

solar cell

2a

semi-transparent solar cell

3

medium

4

sensor element

5

Control / evaluation

6

Power supply unit

7

transmitter housing

7a

Plastic transmitter housing

8th

housing wall

9

outer surface

10

Display / operating unit

11

coating

12

foil

13

Dye solar cell

14

Power generation unit

15

Thermoelectric transducer element, Peltier element

16

piezoelectric transducer element

17

inductive transducer element

18

sensor housing

18a

Plastic sensor housing

19

Energy storage unit

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10222822 A1 [0008]
• DE 10227032 A1 [0008]
• DE 102009029305 A1 [0008]
• US 6366436 B2 [0009]
• DE 10126654 A1 [0009]
• DE 102008042972 A1 [0009]
• US 6556447 B2 [0009]
• WO 98/14763 A1 [0009]
• WO 2008/006463 A1 [0012]
• WO 2009/033214 A1 [0023, 0029]
• US 6366436 B [0031]
• US 6556447 B [0031]

Cited non-patent literature

• German standards DIN EN 60529 [0010]
• DIN 40 050 [0010]
• Industry standard NEMA 250 [0010]
• European standards EN 60079-xx [0011]
• US standards FM36xx [0011]
• Canadian standard C22.2 [0011]
• international standard IEC 60079-18 [0011]
• Standards DIN EN 50 014 ff [0011]
• European standards EN 60079-xx [0031]
• US standards FM36xx [0031]
• Canadian standard C22.2 [0031]
• international standard IEC 60079-18 [0031]
• Standards DIN EN 50 014 ff [0031]
• European standard EN 60079-11: 2007 [0031]
• European standard EN 60079-7: 2007 [0031]
• European standard EN 60079-1: 2007 [0031]
• EN 60079-18: 2004 [0031]
• European standards comparable standards, such as FM3600, FM3610 or C22.2 no. 157 [0031]

Claims (10)

Contraption ( 1 ) of process automation for determining or monitoring at least one physical, biological or chemical process variable of a medium ( 3 ), consisting of at least one sensor element ( 4 ), at least one control / evaluation unit ( 5 ) connected to the sensor element ( 4 ) measured process value and outputs at least as a measured value of the process variable and at least one power generation unit ( 14 ) which, at least in part, the control / evaluation unit ( 5 ) and at least partially the sensor element ( 4 ) supplied with the energy required for operation, characterized in that at least the power generation unit ( 14 ) integral part of a transmitter housing ( 7 . 7a ) and / or a sensor housing ( 18 . 18a ). Apparatus according to claim 1, characterized in that the power generation unit ( 14 ) in at least one housing wall ( 8th ) of the transmitter housing ( 7 . 7a ) and / or the sensor housing ( 18 . 18a ) is integrated as a supporting structural element. Device according to claim 2, characterized in that the power generation unit ( 14 ) in the housing wall produced by an injection molding process ( 8th ) of the plastic transmitter housing ( 7a ) and / or the plastic sensor housing ( 18a ) is integrated. Device according to at least one of the preceding claims, characterized in that the power generation unit ( 14 ) with a in the transmitter housing ( 7 . 7a ) power supply unit ( 6 ) and that the power generation unit ( 14 ) the device ( 1 ) at least partially supplied with the energy required for operation. Apparatus according to claim 4, characterized in that an energy storage unit ( 19 ) in the transmitter housing ( 7 . 7a ) provided by the power generation unit ( 14 ) cached energy. Device according to at least one of the preceding claims, characterized in that the power generation unit ( 14 ) as at least one solar cell ( 2 . 2a ), at least one thermoelectric transducer element ( 15 ), at least one piezoelectric element ( 16 ) and / or at least one inductive transducer element ( 17 ) is configured. Apparatus according to claim 6, characterized in that the solar cell ( 2 . 2a ) as a coating ( 11 ) on at least one outer surface of the transmitter housing ( 7 . 7a ) is applied. Device according to claim 7, characterized in that the coating ( 11 ) of the solar cell ( 2 . 2a ) as a foil ( 12 ) or as dye solar cell ( 13 ) on the transmitter housing ( 7 . 7a ) is configured. Apparatus according to claim 8, characterized in that a display / operating unit ( 10 ) in the transmitter housing ( 7 . 7a ) and that the solar cell ( 2a ) made of the partially transparent material as a sight glass above the display / control unit ( 10 ) is arranged. Device according to at least one of the preceding claims, characterized in that it is in the process variable in particular the level, the density, the viscosity, the temperature, the pH, the substance content of a particular substance, the pressure, the humidity or the flow of the medium ( 3 ).

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