PROCESS FOR ADJUSTING A GAS SUPPLY SYSTEM AND GAS SUPPLY SYSTEM WITH ADJUSTMENT FUNCTION

Abstract

A process (100) for adjusting a gas supply system (300, 400) includes a calibration step for calibrating (101) a gas sensor (303, 401) at a first calibration time (t1) with a defined concentration of test gas. A first calibration result (S1) is determined during the calibration. At least one gas supply measured value (M1) is determined at a time (t2) preceding the first calibration time (t1). A determination step determines (103) a gas supply reference value (G1) by the at least one gas supply measured value (M1) being put into a mathematical relationship with the first calibration result (S1) and with a calibration result (S0) of the gas sensor (303, 401), which was determined at a time preceding the first calibration time (t1). An adjustment step adjusts (105) the gas supply system on the basis of the gas supply reference value (G1).

Claims

1. A process for adjusting a gas supply system, the process comprising the steps of: calibrating a gas sensor at a first calibration time with a defined concentration of test gas, wherein a first calibration result is determined during the calibration, and at least one gas supply measured value is determined at a time preceding the first calibration time; determining a gas supply reference value by putting at least one gas supply measured value into a mathematical relationship with the first calibration result and with a calibration result of the gas sensor, which was determined at another time preceding the first calibration time; and adjusting the gas supply system based on the gas supply reference value.

2. A process in accordance with claim 1, wherein: the calibration of the gas sensor and the determination of the gas supply reference value are repeated at a later time compared to the first calibration time; and the first calibration result is then used as an additional calibration result, a calibration result determined at the later time is used as the first calibration result, and at least one gas supply measured value determined at a time preceding the later time is used as at least one gas supply measured value.

3. A process in accordance with claim 2, wherein the gas supply reference value is determined by the at least one gas supply measured value being multiplied by a ratio of the additional calibration result to the first calibration result.

4. A process in accordance with claim 1, wherein the at least one gas supply measured value is determined by one of the following determination steps: determining an integral of a sensor response of the gas sensor; determining a slope of a sensor response of the gas sensor; determining a response time of a sensor response of the gas sensor; and determining a curve shape of a sensor response of the gas sensor.

5. A process in accordance with claim 1, wherein a warning message is outputted depending on a comparison of the gas supply reference value with a predefined criterion.

6. A process in accordance with claim 5, wherein the warning message for replacing a gas supply of the gas supply system is outputted when a difference between the gas supply measured value and the gas supply reference value differs from a predefined threshold value.

7. A process in accordance with claim 1, wherein a value of the concentration of test gas, which concentration is provided by means of the gas supply, is corrected to the gas supply reference value or the gas supply is controlled with the use of the gas supply reference value such that the concentration of test gas, which concentration is provided by means of the gas supply, corresponds to a predefined threshold value.

8. A gas supply system with adjustment function, the gas supply system comprising: an interface to a gas sensor; a gas supply; and a computing unit configured to determine a first calibration result at a first calibration time to calibrate the gas sensor connected to the interface with a defined concentration of test gas to determine at least one gas supply measured value at a time preceding the first calibration time, and to determine a gas supply reference value by the at least one gas supply measured value being put into a mathematical relationship with the first calibration result and with an additional calibration result of the gas sensor, which additional calibration result was determined at a time preceding the first calibration time, and to adjust the gas supply system based on the gas supply reference value.

9. A gas supply system in accordance with claim 8, wherein: the calibration of the gas sensor and the determination of the gas supply reference value are repeated at a later time compared to the first calibration time; and the first calibration result is then used as an additional calibration result, a calibration result determined at the later time is used as the first calibration result, and at least one gas supply measured value determined at a time preceding the later time is used as at least one gas supply measured value.

10. A gas supply system in accordance with claim 9, wherein the gas supply reference value is determined by the at least one gas supply measured value being multiplied by a ratio of the additional calibration result to the first calibration result.

11. A gas supply system in accordance with claim 8, wherein the computing unit is configured to determine the at least one gas supply measured value by one of the following determination steps: determining an integral of a sensor response of the gas sensor; determining a slope of a sensor response of the gas sensor; determining a response time of a sensor response of the gas sensor; and determining a curve shape of a sensor response of the gas sensor.

12. A gas supply system in accordance with claim 8, wherein a warning message is outputted depending on a comparison of the gas supply reference value with a predefined criterion.

13. A gas supply system in accordance with claim 12, wherein the warning message for replacing a gas supply of the gas supply system is outputted when a difference between the gas supply measured value and the gas supply reference value differs from a predefined threshold value.

14. A gas supply system in accordance with claim 8, wherein a value of the concentration of test gas, which concentration is provided by means of the gas supply, is corrected to the gas supply reference value or the gas supply is controlled with the use of the gas supply reference value such that the concentration of test gas, which concentration is provided by means of the gas supply, corresponds to a predefined threshold value.

15. A gas supply system in accordance with claim 8, wherein the gas supply comprises a gas generator or a gas cylinder.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In the drawings:

[0042] FIG. 1 is a schematic process diagram of a possible embodiment of the process being presented;

[0043] FIG. 2 is a diagram with measured values for carrying out the process being presented;

[0044] FIG. 3 is a schematic view of an embodiment of the gas supply system being presented with an integral gas sensor; and

[0045] FIG. 4 is a schematic view of another embodiment of the gas supply system being presented with an external gas sensor.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0046] Referring to the drawings, Elements having the same function and mode of operation are provided with the same reference numbers in FIGS. 1 through 3.

[0047] FIG. 1 shows a process 100. The process 100 comprises a calibration step 101 for calibrating a gas sensor at a first calibration time with a defined concentration of test gas, wherein a first calibration result is determined during the calibration, and wherein at least one gas supply measured value determined at a time preceding the first calibration time is determined, a determination step 103 for determining a gas supply reference value by the at least one gas supply measured value being put into a mathematical relationship with the first calibration result and with an additional calibration result of the gas sensor, which was determined at a time preceding the first calibration time, and an adjustment step 105 for adjusting the gas supply system on the basis of the gas supply reference value.

[0048] FIG. 2 shows a diagram 200. The diagram 200 extends over its abscissa 201 over time and over its ordinate 203 over a sensor sensitivity in μA/ppm.

[0049] A gas sensor of a gas supply system is calibrated at a first calibration time t1 by, for example, an operator with a test gas cylinder, which contains a defined concentration of target gas or test gas.

[0050] The test particles discharged from the test gas cylinder migrate to a gas sensor, so that the gas sensor measures a gas supply measured value with a sensor sensitivity of, e.g., 1.5 μA/ppm, which corresponds to a first calibration result S1.

[0051] A basic gas supply reference value G0 of, e.g., 2000 ppm.Math.sec, which was determined or preset at a time t0 prior to the first calibration time t1, is set at the gas supply system during the first calibration time t1. Dropping gas generator signals 205 are seen over the use time of the gas sensor and of the gas generator, so that a gas supply measured value (M1), which is determined at a time (t2) preceding the first calibration time (t1), corresponds, for example, to 1000 ppm.Math.sec.

[0052] Starting from the gas supply measured value (M1), the gas supply system would assign a sensitivity of M1/G0=1 μA/ppm to the gas sensor, because the drop of the gas generator signals 205 would be fully assigned to the gas sensor.

[0053] However, the gas generator has, indeed, aged as well, so that an operator calibration at the first calibration time t1 yields a “true” sensor sensitivity of S1=1.5 μA/ppm.

[0054] This means that the gas sensor and the gas generator are aged at the same ratio. Based on this knowledge, a new gas supply reference value G1 can be determined by means of the calculation instruction (1), where S1 corresponds to a first calibration result, S0 to an additional calibration result, M1 to a gas supply measured value and G1 to a gas supply reference value. M1 may be a mean value or median of a number N of last gas generator signals prior to a first calibration operation to determine the first calibration result S1.

G1=M1*(S0/S1)  (1)

[0055] The process 100 may be used, for example, with sensor raw values, of, e.g., currents of an electrochemical sensor or with already calculated concentration values of a sensor.

[0056] A “continuous admission” of gas can be carried out to determine the sensitivity of the gas sensor during a calibration. A stable measured value is then expected and the sensitivity is determined. For example, an integral of a sensor response of the gas response to an admission of a test gas, a jump of a sensor response of the gas sensor in response to the admission of a test gas or a time until the peak of the sensor response of the gas sensor in response to the admission of a test gas can be used to determine the sensitivity of the gas sensor during a calibration.

[0057] FIG. 3 shows a gas supply system 300. The gas supply system 300 comprises an interface 301 to a gas sensor, a gas sensor 303, a gas supply 305 and a computing unit 307. The computing unit is configured to determine a first calibration result at a first calibration time to calibrate the gas sensor with a defined concentration of test gas.

[0058] Furthermore, the computing unit 307 is configured to determine at least one gas supply measured value at a time preceding the first calibration time.

[0059] Furthermore, the computing unit 307 is configured to determine a gas supply reference value by the at least one gas supply measured value being put into a mathematical relationship with the first calibration result and with an additional calibration result of the gas sensor, which was determined at a time preceding the first calibration time.

[0060] Furthermore, the computing unit 307 is configured to adjust the gas supply system 300 on the basis of the gas supply reference value.

[0061] In the example shown in FIG. 3, the gas sensor 303 is connected to the interface 301 in a communicative manner via an electrical connection, for example, a cable or a soldered connection.

[0062] FIG. 4 shows a gas supply system 400. The gas supply system 400 is identical to the gas supply system 300 according to FIG. 3 with the exception that the interface 301 is connected to an external gas sensor 401 in, for example, a gas measuring device 407 via a wireless interface. The gas supply system 400 correspondingly forms a portable module for testing different gas sensors.

[0063] The interface 301 may comprise a first communication module 403 for wireless communication via, e.g., WLAN, Bluetooth, Nearfield Communication, Zigbee or a mobile wireless device signal, e.g., 5G, and a second communication module 405 for connecting a cable, e.g., a COM port or a USB port.

[0064] The gas supply system 400 may optionally comprise an output unit 409, e.g., an LED, a speaker and/or a display, in order for warning messages, e.g., an instruction to replace the gas sensor 401, to be outputted.

[0065] While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

LIST OF REFERENCE NUMBERS

[0066] 100 Process [0067] 101 Calibration step [0068] 103 Determination step [0069] 105 Adjustment step [0070] 200 Diagram [0071] 201 Abscissa [0072] 203 Ordinate [0073] 205 Gas generator signals [0074] t1 First calibration time [0075] S1 First calibration result [0076] M1 Gas supply measured value [0077] t2 Preceding time [0078] G0 Gas supply reference value [0079] G1 New gas supply reference value [0080] 300 Gas supply system [0081] 301 Interface [0082] 303 Gas sensor [0083] 305 Gas supply [0084] 307 Computing unit [0085] 400 Gas supply system [0086] 401 External gas sensor [0087] 403 First communication module [0088] 405 Second communication nodule [0089] 407 Gas measuring device [0090] 409 Output unit