RADIOMETRIC FILL LEVEL MEASURING DEVICE WITH REFERENCE SCINTILLATOR

Abstract

A method for compensating a measurement deviation of a first scintillator and/or a photodetector of a radiometric fill level measuring device is provided, including detecting, by a second scintillator, radioactive emissions from the second scintillator; transmitting, in response to radioactive emissions, a first light signal from the first scintillator and a second light signal from the second scintillator, the first light signal being different from the second light signal; receiving, by the photodetector, the first light signal from the first scintillator and the second light signal from the second scintillator, and converting the light signals into electrical signals; comparing the electrical signals with deposited reference signals by means of a comparator; and adjusting the gain of the photodetector in response to comparing the electrical signals and stored reference signals. A radiometric fill level measuring device for fill level measurement, for density measurement, and/or for mass flow measurement is also provided.

Claims

1. A method for compensating a measurement deviation of a first scintillator and/or of a photodetector of a radiometric fill level measuring device for fill level measurement, comprising: detecting, by a second scintillator, radioactive emissions of the second scintillator; transmitting, in response to radioactive emissions, a first light signal from the first scintillator and a second light signal from the second scintillator, the first light signal being different from the second light signal; receiving, by the photodetector, the first light signal from the first scintillator and the second light signal from the second scintillator, and converting the received light signals into electrical signals; comparing, by a comparator, the electrical signals to stored reference signals; and adjusting a gain of the photodetector in response to the comparing of the electrical signals and stored reference signals.

2. The method of claim 1, further comprising: determining a current temperature and the reference signal stored in a manner suitable for the current temperature.

3. The method of claim 1, wherein the measurement deviation is a function of temperature, and the reference signals to match the temperature are stored in a comparison table.

4. The method of claim 1, wherein the first scintillator is adjacent to the second scintillator.

5. The method of claim 1, wherein the measurement deviation of the first scintillator and/or of the photodetector is caused by aging of the first scintillator and/or of the photodetector.

6. The method of claim 1, wherein a discrimination, by a discriminating device, of the first light signal from the first scintillator and of the second light signal from the second scintillator, is performed on the basis of a different transit time, a different color, and/or a different intensity of light signals.

7. The method of claim 1, wherein the second scintillator is one of the following scintillators: lutetium aluminum garnet (LuAG), cerium-doped lutetium yttrium silicate (LYSO), lutetiumoxyorthosilicate (LSO), yttrium aluminum perovskite (cerium) (YAP:Ce), yttrium aluminum garnet (YAG), and/or a similar scintillator.

8. The method of claim 1, further comprising: transmitting an alarm when neither the first light signal is transmitted and/or received by the first scintillator nor the second light signal is transmitted and/or received by the second scintillator.

9. The method of claim 1, wherein the second scintillator is shielded from a gamma emitter and/or a further external radiation source.

10. A radiometric fill level measuring device for fill level measurement, for density measurement, and/or for mass flow measurement, the fill level measuring device comprising: a first scintillator configured to detect radioactive emissions from a gamma emitter and, in response to the radioactive emissions, to emit a first light signal; a second scintillator configured to detect radioactive emissions from the second scintillator and, in response to the radioactive emissions, to transmit a second light signal, the second light signal being different from the first light signal; a photodetector configured to receive and to convert the first light signal and the second light signal into electrical signals; and a comparator configured to compare the electrical signals with stored electrical reference signals, wherein a gain of the photodetector is adjusted in response to a comparison of the electrical signals and stored reference signals.

11. The device of claim 10, further comprising: a discriminating device configured to discriminate the first light signal and the second light signal based on a different signal travel time, a different color, and/or an intensity of the first light signal and the second light signal.

12. The device of claim 10, wherein the second scintillator is one of the following scintillators: lutetium aluminum garnet (LuAG), cerium-doped lutetium yttrium silicate (LYSO), lutetiumoxyorthosilicate (LSO), yttrium aluminum perovskite (cerium) (YAP:Ce), yttrium aluminum garnet (YAG), and/or a similar scintillator.

13. A nontransitory computer-readable storage medium having a program stored therein, which, when executed on a processor of a radiometric fill level measuring device, instructs the radiometric fill level measuring device to carry out a method according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] FIG. 1 shows a schematic sketch of a radiation-based fill level measuring device according to an embodiment;

[0043] FIGS. 2a to 2e show schematic sketches of a subsystem according to an embodiment; and

[0044] FIG. 3 shows a flowchart of a method according to an embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

[0045] FIG. 1 shows a schematic sketch of a radiometric fill level measuring device 10. The functional components of the fill level measuring device 10 are shown as logical blocks. At least some of these logical blocks may be implemented as hardware, as software, or also partly as hardware and partly as software. The logical blocks may be physically separated or located on the same component. For example, the comparator 47 may be implemented as independent hardware, as part of a chip, and/or as software running on the processor unit 48.

[0046] The radiometric fill level measuring device 10 has a scintillator arrangement 30 that is configured to detect radioactive emissions from a gamma emitter 20. Between the gamma emitter 20 and the scintillator arrangement 30 there is a container 55, which contains a filling material 50 with a filling level 57. The scintillator arrangement 30 may have a first scintillator 31 and a second scintillator 32. The scintillators 31 and 32 emit light signals in response to radioactive emissions. In this drawing, the scintillator assembly 30 is combined with a photodetector 40 to form a subsystem 39 (dashed), which is shown below (i.e., in FIGS. 2a to 2e) in various embodiments.

[0047] The light signals from the first and second scintillator are received by the photodetector 40 and converted into electrical signals. Photodetector 40 may be a photomultiplier or photomultiplier tube (PMT). Such a photomultiplier has a high-voltage power supply 42, which may be controlled, e.g., by a computing and control unit or processor unit 48. After the photodetector 40 an amplifier 43 is arranged, which amplifies the electrical signals from the photodetector 40. A discriminator or discriminating device 44 is arranged downstream, which divides the electrical signals from the amplifier 43 into signals 45, 46, which are caused by radioactive emissions and are detected by the first scintillator 31 and the second scintillator 32, respectively. The division may, for example, take place based on a different signal propagation time, a different color, and/or intensity of the first or the second light signal. A downstream comparator 47 is set up to compare the electrical signalsfor example, the electrical signals resulting from the second light signalwith stored electrical reference signals. The comparator 47 may be implemented as hardware and/or software. The hardware component may be implemented, for example, as special hardware and/or, for example, as part of a chip that also contains a processor or may also be located in the processor. The electrical reference signals may, for example, maintain temperature curves. The temperature responses may be measured, e.g., during the manufacture of the fill level measuring device 10. The temperature responses may be measured additionally or alternatively also during operation of the fill level measuring device 10. The measured data may be further processed in the processor unit or calculation and control unit 48, e.g., a format adjustment and/or further calculations may be carried out. The measurement data are available at an output 49. This may be implemented, e.g., in the form of a 4 . . . 20 mA loop current, and/or as a field buse.g., with a protocol according to HART, Profibus, Foundation Fieldbus, and/or as a proprietary protocol. The measurement data may be available in a format suitable for communication via wireless local area network (WLAN) and/or for a protocol such as LTE, 5G, etc.

[0048] FIGS. 2a to 2e show schematic sketches of subsystem 39 according to an embodiment. Subsystem 39 comprises the scintillator arrangement 30 and the photodetector 40. In particular, different relative arrangements of scintillator arrangement 30 and photodetector 40 are shown. It becomes clear, for example, that in all the embodiments shown, the first scintillator 31 and the second scintillator 32 are arranged adjacent to each other.

[0049] FIG. 2a shows an embodiment in which the first scintillator 31 and the second scintillator 32 are arranged side-by-side in front of the photodetector 40. FIG. 2b shows an embodiment in which the second scintillator 32 is incorporated into the first scintillator 31 or is arranged within a contour of the first scintillator 31. In FIG. 2c, the second scintillator 32 is incorporated into the first scintillator 31 in a dissolved form and/or distributed within a contour of the first scintillator 31. FIG. 2d shows an embodiment where the second scintillator 32 is placed between the first scintillator 31 and the photodetector 40. Light pulses from the first scintillator 31 pass at least partially through the second scintillator 32 before they are detected by the photo-detector 40. In FIG. 2e, the second scintillator 32 is arranged between the first scintillator 31 and the photodetector 40, similar to FIG. 2d. Furthermore, a further photodetector 41 is shown, which preferably or exclusively receives signals from the first scintillator 31. This design can also be used to detect the different light signals on the basis of their different signal propagation times.

[0050] The embodiments shown and/or other embodiments may have an optional partition wall 33 by which the second scintillator 32 is shielded from the gamma emitter 20 and/or another external radiation source. For example, as shown in FIG. 2a, the partition wall 33 can be arranged in a U-shape around the second scintillator 32 so that its light radiation is detected by the photodetector 40, but the second scintillator 32 does not receive and/or detect any radioactive emissions. In the embodiment of FIG. 2d, the partition wall 33 can be arranged laterally around the second scintillator 32 so that its light radiation is detected by the photodetector 40 but the second scintillator 32 does not receive and/or detect any radioactive emissions.

[0051] FIG. 3 shows a flowchart 60 of a method according to an embodiment. In a step 61, radioactive emissions of the second scintillator 32 are detected by means of a second scintillator 32 (see FIGS. 2a to 2e). In a step 62, in response to radioactive emissions, a first light signal is transmitted from a first scintillator 31 and a second light signal is transmitted from the second scintillator 32. The first light signal differs from the second light signal, e.g., in terms of amplitude, transit time, and/or color. In a step 63, the first light signal is received by the first scintillator 31 and the second light signal is received by the second scintillator 32 by means of the photodetector 40, and the light signals are converted into electrical signals. In a step 64, the first light signal and the second light signal are compared, e.g., by means of a comparator 47 (see FIG. 1). In a step 65, a gain of the photodetector 40 and/or other components of the radiometric fill level measuring device 10 is adjusted in response to the comparison of the electrical signals and stored reference signals.

[0052] In addition, it should be noted that comprehensive and comprising do not exclude other elements or steps and the indefinite articles a or one do not exclude a multitude. It should also be noted that features or steps described with reference to one of the above embodiments may also be used in combination with other features or steps of other embodiments described above. Reference marks in the claims are not to be considered as restrictions.

LIST OF REFERENCE SIGNS

[0053] 10 radiation-based measuring device

[0054] 20 gamma emitter

[0055] 30 scintillator arrangement

[0056] 31 first scintillator

[0057] 32 second scintillator

[0058] 33 optional partition wall

[0059] 40 photodetector

[0060] 41 further photodetector

[0061] 42 high-voltage power supply

[0062] 43 amplifier

[0063] 44 discriminating device

[0064] 45, 46 signals

[0065] 47 comparator

[0066] 48 processor unit

[0067] 49 output

[0068] 50 filling material

[0069] 55 container

[0070] 57 filling level

[0071] 60 flowchart

[0072] 61-65 steps