Method for verifying a clamp-on ultrasonic measuring device

Description

[0001] The invention relates to a method for verifying a clamp-on ultrasonic measuring device in measurement and automation technology in order to determine a condition of the measuring device.

[0002] As with all other measuring devices, clamp-on ultrasonic measuring devices, such as those shown in DE102018133476A1, undergo changes in the properties of the measuring device itself during operation. This negatively impacts the measuring performance of such devices, which is why the devices undergo a condition check from time to time.

[0003] EP2607864B1 describes a method for in-line testing of a flowmeter, in which a calibrated clamp-on ultrasonic measuring device is arranged in series with a flowmeter to be calibrated.

[0004] DE 10 2015 106 897 A1 also describes methods for testing an ultrasonic flowmeter based on the transit time difference.

[0005] For a condition check, the clamp-on ultrasonic measuring device is attached to a standard measuring section and measurement results of measured quantities are evaluated.

[0006] This checks whether the measured values ​​are within a validity range.

[0007] The verification is time-consuming because the measured values ​​must first be transferred to an evaluation device in order to then start the actual analysis.

[0008] The object of the invention is to propose a simple and robust verification of a clamp-on ultrasonic measuring device.

[0009] The object is achieved by a method according to independent claim 1 and by a clamp-on ultrasonic measuring device according to independent claim 6.

[0010] In a method according to the invention for verifying a clamp-on ultrasonic measuring device, the measuring device comprising: at least two ultrasonic transducers configured to transmit and receive ultrasonic signals, an electronic measuring / operating circuit configured to operate the at least one ultrasonic transducer and to provide measured values ​​of at least one measured variable and to carry out the verification, wherein the electronic measuring / operating circuit has a memory, the method comprising the following steps: mounting the measuring device on a standard measuring section; wherein the standard measuring section is one from the following list: measuring block, measuring rod; switching on a verification mode of the electronic measuring / operating circuit; transmitting at least one ultrasonic signal with at least one ultrasonic transducer and receiving the ultrasonic signal with at least one ultrasonic transducer;Acquiring at least one measured value of at least one verification variable of the ultrasonic signal and comparing the measured value with a specification value of the verification variable stored in memory; outputting a verification result; terminating the verification mode. ;

[0011] In this way, verification can be carried out much faster and easier than before.

[0012] In one embodiment of the procedure, the verification variable is a measurement variable from the following list: Signal amplitude of a received ultrasonic signal; signal propagation time of an ultrasonic signal; speed of sound; propagation time difference between two ultrasonic signals which are transmitted and received in pairs by two ultrasonic transducers, in particular without the presence of a flowing medium; signal-to-noise ratio; signal shape given, for example, by a rise time, fall time, amplitude, frequency; correlation between a received ultrasonic signal and an expected ultrasonic signal.

[0013] A measuring tube can be empty, partially filled, or completely filled with a liquid. A measuring block or measuring rod can be used to easily check whether the set values ​​are being met.

[0014] In one embodiment of the method, the measuring section is made of at least one of the following materials: plastic, metal.

[0015] By selecting a suitable material, the measuring section and the ultrasonic transducers can be matched. This can, for example, reduce transmission losses due to interface reflections.

[0016] In one embodiment of the method, the verification result comprises a history of measured values ​​with respect to a specification variable.

[0017] Thus, a statement can be made about the stability of a state of the measuring device.

[0018] In one embodiment of the method, the verification result includes a prediction regarding a minimum operating time until a target state is left.

[0019] In this way, a re-verification of the measuring device can be planned in advance. The invention is described below using exemplary embodiments. Fig. 1describes a sequence of an exemplary method according to the invention for verifying the clamp-on ultrasonic measuring device; Fig. 2 shows an exemplary clamp-on ultrasonic measuring device according to the invention; Fig. 3 shows an example ultrasonic transducer; Figs. 4 b) to c) show exemplary standard measuring sections for implementing the procedure.

[0020] Fig. 1 describes a sequence of an exemplary method 100 according to the invention, in which in a first method step 101 the clamp-on ultrasonic measuring device (1) is mounted on a standard measuring section 40, which standard measuring section can be formed, for example, by a measuring tube 41, a measuring block 42 or a measuring rod 43, see Figs. 4 b) to c) .

[0021] In a second method step 102, an electronic measuring / operating circuit 20 of the clamp-on ultrasonic measuring device (see Fig. 2) a verification mode is activated. For example, parameters of a last-used measuring point can be saved so that the clamp-on ultrasonic measuring device can be easily reconfigured for this measuring point in the event of a positive verification result.

[0022] In a third method step 103, at least one ultrasonic transducer 10 of the clamp-on ultrasonic measuring device is caused to emit at least one ultrasonic signal and at least one ultrasonic transducer is caused to receive the at least one ultrasonic signal.

[0023] In a fourth method step 104, the received ultrasonic signal is evaluated by the electronic measuring / operating circuit in order to determine at least one measured value of at least one verification variable of the ultrasonic signal.

[0024] A verification quantity for determining the condition of the clamp-on ultrasonic measuring device is a measured quantity from the following list, for example: Signal amplitude of a received ultrasonic signal; signal propagation time of an ultrasonic signal; speed of sound; propagation time difference between two ultrasonic signals which are transmitted and received in pairs by two ultrasonic transducers, in particular without the presence of a flowing medium; signal-to-noise ratio; signal shape given, for example, by a rise time, fall time, amplitude, frequency; correlation between a received ultrasonic signal and an expected ultrasonic signal.

[0025] The expert is not limited to this list and can also use other verification parameters.

[0026] A check is then made to determine whether at least one measured value lies within a target range. When determining measured values ​​for multiple verification variables, a check is made to determine whether all measured values ​​lie within the corresponding target ranges. This involves accessing at least one specification value stored in a memory / storage unit of the electronic measuring / operating circuit.

[0027] Upon completion of the check, a verification result is output in a fifth method step 105. The verification result can, for example, indicate whether the clamp-on ultrasonic measuring device can be used further or not. In one embodiment of the method, a minimum operating time of the clamp-on ultrasonic measuring device can be determined through an extended evaluation of the at least one measured value, so that a new verification of the clamp-on ultrasonic measuring device can be planned in advance. The extended evaluation can, for example, be based on distances between the measured values ​​and limit values ​​of the associated target ranges.If several verification variables are used for verification, a verification result can be determined, for example, by means of a trained neural network, whereby training of the network can be carried out by inputting known measured values ​​of verification variables as well as the associated condition / status of the clamp-on ultrasonic measuring device.

[0028] In a sixth method step 106, the verification mode is terminated and, if the result is positive, the clamp-on ultrasonic measuring device is prepared for reuse at a measuring point.

[0029] Fig. 21 outlines an exemplary clamp-on ultrasonic measuring device 1 according to the invention with two ultrasonic transducers 10 mounted on the outside of a measuring tube 30, as well as an electronic measuring / operating circuit 20 for operating the ultrasonic transducers and for providing measured values ​​of at least one property of a medium located in the measuring tube. The medium property can, for example, be one of the following measured variables: sound velocity, flow velocity, volume flow, and others.

[0030] According to the invention, the electronic measuring / operating circuit has a memory unit 21 in which at least one specification value is stored so that the method according to the invention can be carried out.

[0031] The functionality of clamp-on ultrasonic measuring devices is known to those skilled in the art.

[0032] Fig. 3shows an exemplary ultrasonic transducer 10, which has a transducer element 11, in particular a piezo element, which is arranged on a coupling element / ultrasound transmitter 12. The coupling element / ultrasound transmitter is contacted with the measuring tube 30 via a side facing away from the transducer element and is configured to transmit ultrasonic signals between the transducer element and the measuring tube and vice versa.

[0033] Fig. 4 b) to c) outline exemplary standard measuring sections 40 by means of which the clamp-on ultrasonic measuring device and in particular the ultrasonic transducers of the clamp-on ultrasonic measuring device can be verified in accordance with the method according to the invention.

[0034] Fig. 4 a)shows a standard measuring section not according to the invention with a measuring tube 41 to which the ultrasonic transducers 10 are mounted. As outlined here, the arrangement can be designed such that an ultrasonic signal is simply reflected on a wall of the measuring tube on a side of the measuring tube 41 opposite the ultrasonic transducer. Since the measuring tube is used exclusively for verification purposes, it retains its properties and can therefore be used repeatedly for verification. The measuring tube can be at least partially filled with a liquid medium for verification. With a measuring tube as a standard measuring section, several ultrasonic signal reflections take place at different interfaces between two different media, so that for verification several

[0035] Ultrasonic signal reflections can be used.

[0036] Fig. 4 b)shows a standard measuring section with a measuring block 42. In a measuring block, ultrasonic signal reflection occurs primarily at interfaces between the surroundings of the measuring block and the measuring block. This results in a clearer and less noisy ultrasonic signal for a receiving ultrasonic transducer.

[0037] Fig. 4 c) sketches a standard measuring section with a measuring rod 43, with the ultrasonic transducers arranged at opposite ends of the measuring rod. In this case, the ultrasonic signal is not reflected, but is transmitted directly via the measuring rod, i.e., without deflection between the ultrasonic transducers. List of reference symbols

[0038] 1 Clamp-on ultrasonic measuring device 10 Ultrasonic transducer 11 Transducer element 12 Coupling body 20 Electronic measuring circuit 21 Memory unit 30 Measuring tube 40 Standard measuring section 41 Measuring tube 42 Measuring block 43 Measuring rod 100 Procedure 101 First process step 102 Second process step 103 Third process step 104 Fourth process step 105 Fifth process step 106 Sixth process step

Claims

1. Method (100) for verifying a clamp-on ultrasonic measuring device (1), where the measuring device comprises: at least two ultrasonic transducers (10) for transmitting and receiving ultrasonic signals, an electronic measuring / operating circuit (20) set up for operating the at least one ultrasonic transducer and for providing measured values of at least one measured variable and for carrying out the verification, wherein the electronic measuring / operating circuit has a memory unit (21), wherein the method comprises the following steps: Mounting the measuring device on a standard measuring section (30) in a first process step (101), wherein the standard measuring range (40) is one from the following list: measuring block (42), measuring rod (43); Switching on a verification mode of the electronic measuring / operating circuit in a second method step (102); Transmitting at least one ultrasonic signal with at least one ultrasonic transducer and receiving the ultrasonic signal with at least one ultrasonic transducer in a third method step (103); Determination of at least one measured value of at least one verification variable of the ultrasonic signal and comparison of the measured value with at least one specification value of the verification variable stored in the memory unit in a fourth method step (104); Outputting a verification result in a fifth method step (105); Ending the verification mode in a sixth process step (106).

2. Method according to claim 1, wherein the verification variable is a variable from the following list: Signal amplitude of a received ultrasonic signal; Signal propagation time of an ultrasonic signal; Speed of sound; Time difference between two ultrasonic signals which are transmitted and received in pairs by two ultrasonic transducers, in particular without the presence of a flowing medium; Signal-to-noise ratio; Signal shape given, for example, by a rise time, fall time, amplitude, frequency; Correlation between a received ultrasonic signal and an expected ultrasonic signal.

3. Method according to claim 1 or 2, wherein the standard measuring section (40) is made of at least one of the following materials: Plastic, metal.

4. Method according to any of the preceding claims, wherein the verification result comprises a progression of measured values relating to a specification variable.

5. Method according to any of the preceding claims, wherein the verification result contains a prediction regarding a minimum operating time until a target state is exited.

6. Clamp-on ultrasonic measuring device (1) adapted to implement the method according to any one of the preceding claims: at least two ultrasonic transducers (10) set up for emitting and receiving ultrasonic signals, which are mounted or can be mounted on a measuring tube, an electronic measuring / operating circuit (20) set up for operating the at least one ultrasonic transducer and for providing measured values of at least one measured variable and for carrying out the verification, wherein the electronic measuring / operating circuit has a memory unit (21) in which at least one specification value is stored.