Gas measuring instrument

Abstract

The invention relates to a gas measuring instrument. The gas measuring instrument comprises a chemical gas sensor and a test unit. The test unit comprises a base, a gas channel arrangement with a first gas channel and at least one further gas channel arranged on the base and at least one electrochemical gas generator, wherein the at least one gas generator is configured for conducting at least one test gas in a first state into the first gas channel and in at least one further state into the at least one further gas channel, wherein the first gas channel and the at least one further gas channel are each configured for conducting the at least one test gas to the gas sensor, and wherein the first gas channel is different from the at least one further gas channel.

Description

Technical Field

[0001] This invention relates to a gas measuring instrument, a tester for the gas measuring instrument, and a test method for testing the gas measuring instrument. Background Technology

[0002] Gas measuring instruments, especially gas alarm devices with gas sensors, must undergo functional testing at regular intervals to ensure their proper functioning.

[0003] During operation, the gas measuring instrument may experience limited functionality due to factors such as blockage of the opening through which it connects to the ambient medium, or due to mechanical or electrical interference.

[0004] To identify limited functionality of a gas measuring instrument and to repair or replace it, a method is known in which the gas sensor of the gas measuring instrument is loaded with a test gas through a gas channel and the corresponding sensor response is evaluated. Because a single gas channel is used, the influence of interfering variables in all sensor responses cannot be accurately determined, which may lead to erroneous measurements.

[0005] Therefore, US 2008 / 0282765 A1 describes a gas sensor having a single gas channel, at least one gas sensor, a gas generator, and a pump. The pump conducts test gas generated by the gas generator to the gas sensor for testing.

[0006] US 5,667,558 A describes a gas scrubber with an outlet gas sensor and a pump for delivering chemicals into a scrubbing suspension to scrub the gas.

[0007] US 4,742,708 A describes an electrochemical gas detection system having an electrochemical sensor and a housing with a reservoir for an electrolyte. Furthermore, the gas detection system includes a calibration system having a calibration gas source for calibrating the gas detection system. Summary of the Invention

[0008] The objective of this invention is to provide an improved gas measuring instrument. In particular, the objective is to provide the possibility of testing the current functionality of a gas measuring instrument.

[0009] The aforementioned task is achieved through the features of the independent claims. Further features and details of the invention are derived from the dependent claims, the specification, and the drawings. Hereinafter, the features and details described in connection with the gas measuring instrument or tester are also applicable to the test method according to the invention, and vice versa, so that the disclosures relating to various aspects of the invention are always mutually referential or can be mutually referenced.

[0010] Therefore, a gas measuring instrument is introduced.

[0011] The gas measuring instrument includes: at least one chemical gas sensor for converting the analyte, the chemical gas sensor having an surrounding sensor space; at least one open area forming a breathable connection between the sensor space and the environment of the gas measuring instrument; and at least one test unit.

[0012] The test unit includes a gas channel device with multiple gas channels and at least one gas generator, the gas generator being configured to conduct at least one test gas via the gas channel device into a sensor space surrounding a gas sensor during a first time period and a second time period of testing in the test unit. Here, the test gas delivery during the first time period exhibits different transmission characteristics than during the second time period due to the channel structure of the respective gas channels and / or due to the characteristics of the at least one test gas.

[0013] In the context of the invention described herein, the term "test" should be understood as a procedure used to verify or check functionality. Accordingly, testing checks whether the intended functions are correctly performed and / or provided.

[0014] In the context of the invention described herein, test gas should be understood as a gas having a known, pre-given composition and concentration of the substances contained in the test gas.

[0015] The channel structure of a gas channel should be understood as the structural characteristics of the gas channel, such as the shape, size, cross-sectional area, surface properties and / or length of the gas channel.

[0016] In the context of the invention described herein, a gas generator should be understood as a device consisting of at least one generator electrode and a counter electrode, wherein a common counter electrode can be provided when multiple gas generators are used. Therefore, the gas generator can also generate test gas when using suitable tablets, such as silver sulfide tablets.

[0017] The opening area according to the invention can, for example, shield larger particles through a filter, while allowing the transfer of the environmental medium, particularly ambient air. Typically, a gas sensor is configured, outside of testing, via a test unit to detect the gaseous components in the environmental medium, particularly ambient air, entering through the opening area.

[0018] The sensor space is a space surrounding the gas sensor and accessible to the ambient medium containing the analyte to be evaluated via at least one opening. The sensor space is preferably spatially bounded by the sensor housing of the gas measuring instrument.

[0019] In the context of the invention described herein, reference values ​​should be understood as a plurality of pre-given values ​​that may be mathematically related to comparison values. Reference values ​​may include single or multiple values, particularly curve-like processes (Kurvenverlauf). Reference values ​​may include positive and / or negative values, and are given in particular as bands of value ranges. Reference values ​​may be mathematical manipulations and / or compressions of one or more values.

[0020] In the context of the invention described herein, a computing unit should be understood as any programmable device. In particular, a computing unit can be a circuit, such as an ASIC, at least one processor, or a distributed system. Specifically, a computing unit is a computer.

[0021] The gas measuring instrument described herein consists of at least one chemical gas sensor and at least one test unit. The chemical gas sensor chemically transforms the gas flowing into it to generate a sensor response. The gas sensor may be a catalytic combustion sensor (Pellistor), i.e., a heat flux sensor that burns gas and measures the heat flux generated, or an electrochemical sensor that reduces or oxidizes gas and measures the electrical properties of the reduced or oxidized gas.

[0022] The test unit according to the invention preferably includes a structure, such as a base, which may be made of a preferably airtight material, such as plastic. The base may in particular have a circular, preferably circular, shape and be connected to a gas channel device. The gas channel device may, for example, be arranged in a cross shape within the circular base.

[0023] The test unit is specifically configured to test the functionality of gas measuring instruments. To this end, the test unit can test the functionality, i.e., the corresponding functions, of gas measuring instruments, especially gas sensors, by supplying test gas to the gas sensor via a gas generator.

[0024] To supply gas to the gas sensor, the test unit includes a gas channel device having multiple gas channels, i.e., at least one gas channel, each gas channel having a corresponding channel structure. Test gas is transferred via these multiple gas channels during a first time period and a second time period of testing within the test unit. These two time periods preferably have little or no overlap in time range that is technically negligible. Alternatively, an overlap of the two time ranges can be provided for the test according to the invention through the test unit.

[0025] According to the present invention, in addition to the first time period and the second time period, it is also possible to set at least one additional time period for the test of the test unit in the design scheme of the gas measuring instrument according to the present invention.

[0026] Due to the different transmission characteristics of each gas channel, the temporal distribution of the concentration of the gas to be detected at the detection location in the gas sensor, and consequently the sensor response of the gas sensor, varies during two different time periods when the test gas is supplied. This results in different gas clouds with different concentration temporal distributions generated by supplying the gas sensor with the test gas during the different time periods, and these concentration temporal distributions may also be affected differently by environmental parameters, such as wind, due to these differences. In particular, the functionality of the gas sensor can be tested by supplying the gas sensor with the test gas during a first time period, and the functionality of the gas measuring instrument's opening can be tested by supplying the gas sensor with the test gas during a second time period.

[0027] Furthermore, the sensor values ​​determined when the gas sensor is supplied with test gas during the first time period and the sensor values ​​determined when the gas sensor is supplied with test gas during the second time period can be mathematically correlated with each other in order to infer the characteristics of the gas measuring instrument or the environment of the gas measuring instrument.

[0028] In particular, the two transport characteristics may differ during the two time periods due to different interactions or environmental influences on the gas flowing through the gas channel device. Preferably, for this purpose, the first gas channel and at least one second gas channel of the gas channel device are constructed differently and / or different test gases are used during the two time periods.

[0029] In an advantageous embodiment, the gas channel device has at least two gas channels, wherein at least one test gas is conducted to the sensor space via a first gas channel during a first time period and via a second gas channel during a second time period. Thus, the location of test gas transmission during the first time period differs from the location of test gas transmission during the second time period. In principle, the gas channel device may also have at least one additional gas channel besides the first and second gas channels.

[0030] In an advantageous variation of the aforementioned embodiment, the first gas channel and the second gas channel differ in their channel structures.

[0031] It can be specified that the difference between the first and second gas channels is that the opening of the first gas channel is closer to the gas sensor than the opening of the second gas channel.

[0032] Alternatively or additionally, it may be specified that the second gas passage opening is closer to at least one opening region than the first gas passage opening.

[0033] By utilizing the different channel structures of the various gas channels in the described gas measuring instrument, test gases with different flow characteristics and thus different transmission characteristics for supplying gas to the gas sensor can be generated. For example, a first gas channel with a gas channel geometry ending close to the gas sensor can be used to test the gas sensor itself, while a gas channel with a gas channel geometry ending further away from the gas sensor than the first gas channel can be used to test the flow characteristics of the opening region of the gas measuring instrument and / or the sensor input end.

[0034] With a small distance between the end of the gas channel and the gas sensor, environmental influences, such as secondary currents (Nebenströmungen) caused by ambient wind, have minimal impact on the corresponding sensor values. Accordingly, such a gas channel geometry is particularly advantageous for testing the functional capabilities and sensitivity of gas sensors, since small variances and / or small effects of interfering variables can be expected in the corresponding tests.

[0035] Because environmental influences, such as secondary currents caused by ambient wind, strongly affect the corresponding sensor values ​​when there is a large distance between the end of the gas channel and the gas sensor, and because the opening area of ​​the gas measuring instrument and / or the sensor input end is preferably closer to the end of the gas channel than the gas sensor, such a gas channel geometry is particularly advantageously suited for testing the opening area of ​​the gas measuring instrument and / or the sensor input end. In particular, such a gas channel geometry is particularly advantageously suited for testing the opening area of ​​the gas measuring instrument and / or the sensor input end because the degree of blockage of the opening particularly strongly affects the transmission characteristics of the corresponding test gas between the end of the gas channel and the gas sensor.

[0036] Furthermore, it can be specified that the first gas channel and at least one other gas channel are distinguished from each other by the roughness of their inner surfaces in their channel structures.

[0037] By utilizing the varying roughness of the internal regions of the gas channels in the gas measuring instrument described herein, test gases with different transmission characteristics, particularly different flow characteristics, can be generated for supplying gas to the gas sensor. For example, a first gas channel with a low-roughness, i.e., particularly smooth, inner surface can be used to test the gas sensor itself, while a gas channel with an inner surface having a higher roughness than the first gas channel can be used to test the flow characteristics of the opening region of the gas measuring instrument.

[0038] Because the test gas flows very rapidly through the gas channel due to the low roughness of its inner surface, environmental influences, such as secondary flows caused by ambient wind, have a lower impact on the dense gas cloud at the outlet of the gas channel compared to the case of braked diffused gas output in the discharge region of a rough channel. Accordingly, such a gas channel is particularly advantageous for testing the functional capabilities and sensitivity of gas sensors, as small variances and therefore small effects of interfering variables can be expected in the corresponding tests.

[0039] Because the test gas flowing through the gas channel is subject to a large roughness on its inner surface, it flows more slowly, for example, due to adsorption and desorption processes on the channel walls. This results in a time-delayed gas cloud at the output, which extends over time and appears at a low concentration at the detection location, and is therefore affected differently by environmental factors, such as wind. Accordingly, such a gas channel is particularly advantageous for the opening of a test gas measuring instrument, as its degree of blockage is mathematically related to and consequently correlated with the effects of secondary flows caused by ambient wind.

[0040] Furthermore, it can be specified that at least one gas channel includes a temperature control unit configured to change the temperature inside the gas channel such that the test gas in the first time period differs from the test gas in the second time period in terms of its gas temperature. The test gas in the first time period can here be a different test gas from the test gas in the second time period.

[0041] By adjusting the temperature of the test gas in the gas measuring instrument described herein, test gases with different transmission characteristics can be generated for supplying gas to the gas sensor. For example, a first gas channel can be used together with a temperature control unit for heating the first gas channel to test the gas sensor, while other gas channels in the gas channel device, either without a temperature control unit or with a temperature control unit for cooling the gas channel, can be used to test the flow characteristics of the opening of the gas measuring instrument.

[0042] Because the test gas flows rapidly through the gas channel at high temperatures, it exits as a dense gas cloud, and ambient atmospheric influences, such as wind, have less impact on the dense gas cloud at the outlet of the gas channel compared to when the gas channel is at lower temperatures. Accordingly, heated and / or heatable gas channels are particularly advantageous for test gas sensors, as small variances of interference variables, i.e., small effects, can be expected in the corresponding tests.

[0043] Because the test gas flowing through the gas channel moves slowly at low temperatures, a time-delayed gas cloud is generated at the output. This gas cloud extends over time and appears at a low concentration at the detection location, and is therefore affected and / or can be affected by the environment, such as wind, in different ways. Accordingly, a cooled and / or coolable gas channel is particularly advantageous for the opening of the test gas measuring instrument relative to the ambient atmosphere, since its degree of blockage is mathematically related to and consequently correlated with the effect of secondary flows caused by ambient wind.

[0044] Furthermore, it can be specified that the first gas channel and at least one other gas channel are fluidly connected to each other, particularly through the respective chambers of the gas channels, and that the first gas channel is not in direct fluid contact with the environment of the test unit while at least one other gas channel is in direct fluid contact with the environment of the test unit.

[0045] In order to minimize the impact of environmental influences on the test gas used for testing gas sensors, it is particularly advantageous to have a gas passage with a chamber that does not have direct fluid contact with the environment.

[0046] To maximize the effect of environmental influences on the test gas used in the test gas sensor, a gas passage with a chamber that is in direct fluid contact with the environment is particularly advantageous.

[0047] In a preferred embodiment, at least one gas generator is configured to conduct a different test gas during a first time period via a corresponding gas channel than during a second time period. These two different test gases preferably have two different diffusion coefficients. This achieves different transport characteristics, particularly different concentration time distributions, independent of the structure of the gas channel device.

[0048] In one embodiment, the time interval is located between a first time period and a second time period, during which no test gas is supplied by the gas generator, wherein the time interval is at least 1 minute, particularly at least 30 minutes, and especially preferably at least 2 hours. In this embodiment, there is a clear time separation between the first phase of the test during the first time period and the second phase of the test during the second time period. Thus, the chemical process that takes place during the first time period can be waited for particularly reliably before a new phase of the gas measuring instrument test is carried out during the second time period.

[0049] The test unit of the gas measuring instrument described herein may include at least one computing unit. The at least one computing unit is preferably configured to receive signals from a gas sensor and thereby determine measured values, wherein the computing unit is further configured to determine and output test information during a first time period and / or a second time period, wherein the test information indicates whether the gas measuring instrument is malfunctioning, and wherein the determination of the test information is based on a comparison between the measured value and a predetermined gas sensor threshold, or between a determined parameter of the measured value change process and a predetermined parameter of the change process. Here, the test information may, for example, indicate whether at least one opening area is blocked and / or whether the gas sensor is functioning properly. Various examples of possible operating modes of such a computing unit are given in the following embodiments. The use of a comparison between predetermined measured values ​​or predetermined measured value change processes enables a particularly simple and reliable determination of test information by the computing unit.

[0050] In one example of the aforementioned implementation, the computing unit is configured to perform a comparison between a measured value and a predetermined gas sensor threshold during one of two time periods, and a comparison between a measured value change process parameter and a predetermined change process parameter during the other of the two time periods. Thus, different determination rules are executed during each time period, and these determination rules result in test information.

[0051] Alternatively or supplementarily, an evaluation of multiple past measurements from the first and / or second time periods can be performed using a computational unit. This consideration of the measurement history can lead to particularly reliable evaluations.

[0052] Alternatively or additionally, the computing unit may include at least one control module for controlling components of the gas measuring instrument, such as gas generators. Alternatively or additionally, at least one computing unit may include an analysis module for evaluating various measurements of the gas sensors of the described gas measuring instrument. In particular, at least one computing unit is used to operate the described gas measuring instrument. For this purpose, at least one computing unit may be communicatively connected to the gas sensors and / or the respective gas generators to exchange control commands with them. At least one computing unit may include one or more processors configured to operate the described gas measuring instrument. At least one computing unit may reside in a computer, such as a server, especially in the cloud, and may be communicatively connected to the described gas measuring instrument via a communication interface. Alternatively, at least one computing unit may be at least partially located within the gas measuring instrument itself.

[0053] Furthermore, it can be specified that the calculation unit provided according to the invention is configured to mark the gas sensor or gas measuring instrument as faulty if the difference or quotient between the measured value to be determined by the gas sensor or an intermediate result that can be calculated from it during a first time period and at least one predetermined reference value is greater than a predetermined gas sensor threshold. Additionally, it can mark the opening area as blocked if the difference or quotient between the variable describing the signal (such as decay time, peak height, integral, or an intermediate result that can be calculated from the measured value determined by the gas sensor during a second time period and a predetermined reference value is greater than a predetermined blockage threshold, through which the gas passage is directly connected to the environment.

[0054] The functionality of a gas sensor can be tested by comparing a measured value determined during a test gas supply through a gas channel provided according to the invention, and / or a value obtained through further mathematical processing of the measured value, with a pre-given reference value.

[0055] Since the gas sensor provided according to the present invention is a chemical gas sensor, the gas sensor chemically transforms the test gas under correct, i.e., fault-free functional conditions, so that the concentration of the test gas decreases over time and the measured value determined by the gas sensor changes accordingly.

[0056] If, during the first time period of gas supply to the gas sensor, a comparison between the various measured values ​​and a reference value reveals that the measured values ​​have not changed or have only changed slightly, in a manner such that, for example, the difference or quotient between the measured value and the reference value obtained through further mathematical processing of the measured value is above a pre-given gas sensor threshold, then a faulty function of the gas sensor or gas measuring instrument can be inferred. Accordingly, the computing unit provided according to the invention is configured to mark the gas sensor or gas measuring instrument as faulty in this case and, for example, store the fault message in the memory of the gas sensor, the gas measuring instrument, and / or in the fault memory and / or in the memory of the computing unit. Here, the reference value may, for example, be the sensor value at half the time of the attenuation curve (Abbaukurve) of the reference sensor, or it may relate to the development of characteristic parameters of the corresponding sensor itself.

[0057] The functionality of the gas meter's opening can be tested by mathematically comparing characteristic parameters, such as decay time, peak height, integral, or other characteristic parameters determined during the test gas supply period in a second time interval, with a pre-given reference value. Since secondary flows, such as ambient air, enter and / or the test gas flows out of the gas meter through the opening, the concentration of the test gas is minimized over time when the opening is not blocked. This causes the concentration of the test gas to decrease over time, and the measurement value determined by the gas sensor changes accordingly rapidly. Characteristic parameters describing the level and range of the signal are particularly advantageously suited for testing the opening's functionality. Such characteristic parameters are, for example, the peak height combined with the decay time or the amount of gas conversion at the sensor, which can be represented by integration.

[0058] To check the gas sensor's sensitivity according to specifications, a test gas can be applied to the gas sensor using a gas generator according to the invention. Here, loading is first performed such that a first gas channel is used, for example, which is as independent of environmental conditions as possible and / or does not directly contact the environment.

[0059] In order to evaluate whether unobstructed gas entry to the gas sensor to be tested can be achieved and / or to identify possible blockages or clogging, the test gas is conducted to the gas sensor by means of a gas generator according to the invention, for example through a second gas channel, which facilitates a particularly strong interaction between the test gas and the ambient atmosphere, and is preferably in direct contact with the environment or separated from the environment only through a filter.

[0060] Because of the gas supply from the gas generator provided according to the invention, the gas sensor reacts with a sensor signal not only when gas is supplied through the first gas channel but also when gas is supplied through the second gas channel, the sensor signal being proportional to the concentration of the supplied test gas. The time-varying process of the measured value determined by the gas sensor is evaluated by the analysis unit for the gas supply through the first gas channel and the gas supply through the second gas channel.

[0061] On the one hand, when evaluating measurements in a gas channel, it is possible to perform a comparison between the general shape of the concentration-time distribution curve of the gas sensor and a pre-given reference value, for example, in the form of a fitted function stored in the memory of the analysis unit. This comparison allows for a qualitative assessment of the curve shape of the measurements determined by the gas sensor. This comparison with the fitted function reflects the dynamics of the gas sensor's measurement signal relative to time based on a normalized curve, or, for example, a curve in units of concentration. For this purpose, suitable fitting parameters of a mathematical function can be used in particular.

[0062] To quantitatively evaluate the measurements of the gas channel, mathematical characteristic parameters of the measurements can be used, such as the maximum value, minimum value, half-value width, half-value time of the descending branch, signal level of the measurement at a specific time point in the descending branch (e.g., in units of concentration), area integrals with different boundaries, standard deviation over different value ranges, median, and any other technically suitable mathematical characteristic parameters.

[0063] In particular, the comparison performed by the computing unit to determine the test information preferably depends on the determination of the measured value change process based on the decay time, mathematical derivation, statistical average, maximum value and / or integral, as well as consideration of previous measured values.

[0064] Furthermore, it is possible to derive characteristic quantities from segments of the gas sensor's measurements using extrapolation, these characteristic quantities fully describing the gas sensor's properties. For example, information about the sensor's response characteristics, response time, and dead time can be determined from a plot of the measurements relative to time in units of concentration, using linear extrapolation about a selected range of values ​​between two time points before reaching the maximum value. Accordingly, after reaching the maximum value, information about the sensor's attenuation characteristics and the unblocked flow of gas into the gas sensor can be determined. Other suitable plots of the gas sensor's measurements can be used to evaluate the gas sensor's functionality. For example, the gas sensor's measurements can be plotted relative to the gas dose, i.e., the integral of the measurement's change over time, and the measurements can be evaluated to determine test information.

[0065] In particular, the determined actual values, i.e., the gas sensor's measured values ​​and reference values, can be compared with each other using appropriate mathematical methods. The reference values ​​can, for example, be pre-defined as tolerance zones describing the range of gas sensors and gas generators intended for proper operation. When the gas sensor's measured values ​​deviate from or violate these tolerance zones, various states or malfunctions of the gas sensor can be inferred. For example, the gas sensor may react to the test gas too insensitively, too sensitively, too slowly, or too quickly; the test gas may be transported and / or further processed too quickly or too slowly. In particular, the curve of the measured values ​​may deviate from a pre-defined reference curve in time or in terms of concentration values. Each deviation from the pre-defined reference value is evaluated according to the evaluation logic stored in the evaluation unit, and output to the end user after repeated testing if necessary. In particular, based on the evaluation of the gas sensor's measured values, action recommendations can be output to the user, especially within the range of test information.

[0066] If a comparison between the determined decay time and a reference value reveals a slow change in the measured value, for example, if the difference between the decay time and the reference value is above a pre-given gas sensor threshold, then a faulty function and / or blockage of the opening can be inferred, and the gas measuring instrument can be marked as faulty accordingly. Accordingly, the computing unit provided according to the invention is configured to mark the opening, particularly the opening area, or the gas measuring instrument as faulty in this case, and stores the fault message, for example, in the memory of the gas measuring instrument and / or in a fault memory and / or in the memory of the computing unit. Here, the reference value can be, for example, a sensor value determined, by the decay time, particularly the half-value time, of the decay curve of a reference sensor in a reference chamber with a completely general opening.

[0067] Furthermore, the computing unit can be configured to mark the gas measuring instrument as faulty based on corresponding test information when the measured value after a predetermined time point is greater than or less than a predetermined reference value when the gas is supplied to the gas sensor through a gas channel with a roughness less than that of the inner surface of the respective other gas channels, and to mark the opening as blocked based on corresponding test information when the measured value after a predetermined time point is greater than or less than the predetermined reference value when the gas is supplied to the gas sensor through the respective other gas channels, through which the respective other gas channels are in direct fluid contact with the environment of the gas measuring instrument.

[0068] Since a gas sensor malfunction interferes with the conversion of the test gas, and the resulting change in the test gas concentration is minimal, the functionality of the gas sensor can be inferred from the measured value at the point in time when the conversion of the test gas affects the concentration of the test gas in the reference sensor, and corresponding test information can be output. Therefore, the gas sensor's measured value at that point in time can be evaluated such that if these measured values ​​are greater than a pre-given reference value, or if the measured value differs from the maximum concentration of the test gas only by a pre-given threshold or, depending on the sign of the corresponding measurement signal, by a amount above a pre-given threshold, a malfunction of the gas sensor and the corresponding gas measuring instrument can be assumed.

[0069] Since interference variables should be minimized when testing gas sensors, gas supply through gas channels suitable for particularly rapid gas transmission, especially gas channels with particularly smooth inner surfaces, is particularly advantageous for testing gas sensors.

[0070] Since the interaction between the test gas and the environment is considered when opening the gas measuring instrument, it is appropriate to supply gas to the gas sensor through a gas channel that allows the test gas to interact with the environment for a particularly long period of time. For this purpose, a gas channel with a particularly rough inner surface may be especially suitable. Through a gas channel with a rough inner surface, the test gas is slowed down and flows accordingly slowly, resulting in a slow flow to the gas sensor during the extended period of interaction with the ambient medium.

[0071] Furthermore, the computing unit can be configured to mark the gas sensor and / or gas measuring instrument as faulty via test information when, after a predetermined time point, the measured value is greater than a predetermined reference value or, according to the sign of the corresponding measurement signal, less than a predetermined reference value when the gas sensor is supplied with test gas through a gas channel whose internal temperature is higher than the internal temperature of the respective other gas channels, the measured value is greater than or correspondingly less than a predetermined reference value when the gas sensor is supplied with test gas through the respective other gas channels, after a predetermined time point, the opening through which the respective other gas channels directly contact the environment of the gas measuring instrument via test information is marked as blocked.

[0072] Since interference variables should be minimized when testing gas sensors, gas supply through gas channels suitable for particularly rapid gas transmission, especially through particularly hot gas channels, is particularly advantageous for testing gas sensors.

[0073] Since the interaction between the test gas and the environment is taken into account when testing the opening of the gas measuring instrument, it is particularly advantageous to supply gas to the gas sensor through a gas channel suitable for particularly slow gas transmission, especially through a particularly cold gas channel, for the test opening.

[0074] Furthermore, it can be specified that the computing unit is configured to recalibrate the gas sensor based on the difference between the measured value to be determined by the gas sensor during at least one first state and at least one pre-given reference value, if the difference is greater than or less than a pre-given gas sensor threshold.

[0075] To repair a gas sensor marked as faulty or to continuously adapt the gas sensor to the current condition, the gas sensor can be recalibrated. For this purpose, it can be specified, for example, that a comparison table or allocation logic assigns the respective measured values ​​determined by the gas sensor to the respective values ​​to be output on the output scale (Ausgabeskala), based on the deviation between the measured values ​​determined by the gas sensor during the first state and a pre-given reference value. For this purpose, an alarm threshold can be raised or lowered based on the deviation, from which an alarm sound should be output. In this sense, the alarm sound is also test information. Generally, test information is information indicating the result of a test during at least one of the two time periods according to the invention.

[0076] In particular, it can be specified that the trend of the measurements determined by the gas sensor is used in order to recalibrate the gas sensor. For this purpose, for example, an average of multiple measurements determined at time offsets or any other technically suitable characteristic value can be formed.

[0077] Furthermore, it can be specified that a first gas channel is formed such that the test gas flows through the first gas channel faster than through the second gas channel, and the computing unit is configured to determine the difference between a first time point between the start of test gas supply through the first gas channel and the time point of increase in the measured value of the gas sensor, and another time point between the start of test gas supply through at least one other gas channel and the time point of increase in the measured value of the gas sensor, and infer the diffusion time of the test gas to the measuring instrument based on the difference, and take the diffusion time into account when performing the test.

[0078] By determining such a diffusion time, which can preferably vary according to ambient temperature, variables to be calculated by the calculation unit of the gas measuring instrument, such as decay time or any other variables to be calculated or determined, such as temperature, can be corrected.

[0079] Furthermore, it can be specified that the computing unit is configured to infer the wind speed outside the opening area based on a comparison between the measured value to be determined by the gas sensor during the first time period and the measured value to be determined by the gas sensor during the second time period.

[0080] By comparing the measured values ​​obtained from the gas sensor when the test gas is supplied via a gas channel with rapid gas conduction with the measured values ​​obtained from the gas sensor when the test gas is supplied via a gas channel with slow gas conduction, the characteristics of the interfering variables interacting with the test gas can be inferred, especially the velocity of the secondary flow entering through the opening. Accordingly, based on this comparison, the wind speed outside the gas measuring instrument, i.e., outside the opening area, can be inferred. Applicable here, the greater the deviation from the reference value, the faster the wind speed.

[0081] Furthermore, it can be specified that the test unit includes a first gas generator and at least one additional gas generator, and the calculation unit is configured to supply test gas to the gas sensor through at least one additional gas generator for the case where the gas sensor should be marked as faulty when gas is supplied through the first gas generator, and to mark the gas sensor as fault-free and the first gas generator as faulty and provide corresponding test information for the case where the gas sensor should not be marked as faulty when gas is supplied through the additional gas generator.

[0082] Using multiple gas generators, a verification gas generator, preferably used only when a gas sensor should be marked as faulty, can be used, for example, to check the gas generator on which a test is based, which has resulted in the gas sensor or opening being marked as faulty. Accordingly, verifying the gas generator can prevent the gas sensor or gas measuring instrument from being mistakenly marked as faulty.

[0083] Furthermore, it can be specified that the first gas channel and the second gas channel are arranged in parallel side by side or connected to form at least one maze.

[0084] The labyrinthine gas channels can minimize the environmental impact on the various measurements to be determined using gas sensors.

[0085] In a second aspect, the invention relates to a tester for a gas measuring instrument. The tester includes a possible design of a test unit according to the invention, and an interface for a reversible mechanical and / or communicative connection between the test unit and a gas sensor.

[0086] The tester according to the invention is preferably reversibly connectable to a gas measuring instrument and / or a gas sensor, allowing it to be used to test a large number of gas measuring instruments. Accordingly, with respect to the tester, reference is made to the advantages described in the scope of the introduced gas measuring instruments.

[0087] In a third aspect, the invention relates to a testing method for testing a gas measuring instrument. The testing method includes the following steps:

[0088] a) Provide a gas measuring instrument according to any of the foregoing embodiments;

[0089] b) Manipulate at least one gas generator such that the gas generator conducts at least one test gas into the sensor space surrounding the gas sensor via a gas channel device during a first time period of testing and during a second time period of testing;

[0090] c) Determine the measured values ​​determined by the gas sensor during the first time period and / or the second time period;

[0091] d) Determine and output test information during a first time period and / or a second time period, wherein the test information indicates whether the gas measuring instrument is faulty, and wherein the determination of the test information is based on a comparison between the measured value or a characteristic value calculated therefrom and a predetermined gas sensor threshold or a determined measurement change process parameter calculated according to a predetermined rule and a predetermined change process parameter.

[0092] The described test method is particularly applicable to operating the described gas measuring instrument and the described tester, such that the advantages of the described method are described in relation to the advantages of the gas measuring instrument and / or tester. Attached Figure Description

[0093] Further improvements to the invention can be derived from the following description of some embodiments of the invention, illustrated in the figures. All features and / or advantages, including structural details and spatial arrangements, as known from the claims, description, or drawings, are essential to the invention not only individually but also in various combinations. Schematably, respectively:

[0094] Figure 1 A cross-sectional side view of a possible design for a gas measuring instrument according to the present invention is shown.

[0095] Figure 2 Showing the use of Figure 1 In the case of a gas measuring instrument, a comparison is made between the measurement data determined when gas is supplied through the first gas channel and the measurement data determined when gas is supplied through the second gas channel.

[0096] Figure 3 This shows a comparison of measurement data, which were used in... Figure 1 In the case of a gas measuring instrument, it can be used to determine the impact of ambient wind speed.

[0097] Figure 4 This illustrates other possible design schemes for the gas measuring instrument described, and

[0098] Figure 5 The flowchart illustrates a possible design scheme for the method according to the present invention. Detailed Implementation

[0099] exist Figure 1 The gas measuring instrument 100 is shown in a cross-sectional side view. The gas measuring instrument includes a test unit 101 and a gas sensor 103. The test unit 101 includes a chemically-oriented gas generator 105 for converting analytes of the test gas used in the test gas measuring instrument 100.

[0100] The gas generator 105 consists of a counter electrode and a generator electrode in the first generator chamber 107. Additionally, a separate generator chamber 109 is provided. In particular, it can be specified that the counter electrode is shared by multiple gas generators.

[0101] The first generator chamber 107 is in contact with the first gas passage 111 via a first gas outlet 129, allowing test gas generated by the gas generator 105 to flow into the first gas passage 111 through the first gas outlet 129. To prevent electrolyte that may be stored in the first generator chamber 107 from leaking into the first gas passage 111, the first gas outlet 129 includes a breathable membrane that is permeable to the test gas but sealed to the electrolyte.

[0102] The additional generator chamber 109 is in contact with the second gas passage 113 via an additional gas exhaust opening 131, such that test gas generated by an optional additional gas generator and / or an optional additional generator electrode flows into the second gas passage 113 through the additional gas exhaust opening 131. To prevent electrolyte that may be stored in the additional generator chamber 109 from being discharged into the second gas passage 113, the additional gas exhaust opening 131 includes a selectively permeable membrane that is permeable to the test gas and sealed to the electrolyte.

[0103] Here, the test unit 101 is fixedly connected to the gas sensor 103. Additionally, the test unit 101 is designed to have an interface for communicating and / or mechanically connecting with the gas sensor 103.

[0104] The test unit 101 can be designed as a circular base, with the first gas channel 111 and the second gas channel 113 arranged on the circular base or the first gas channel 111 and the second gas channel 113 integrated into the circular base.

[0105] The first gas passage 111 includes a first chamber 115.

[0106] The second gas passage 113 includes an additional chamber 117 having an opening region 119, which is in contact with the environment via a filter through the opening region, allowing environmental media, such as air, to flow into the chamber 117 or test gas to flow out of the chamber 117.

[0107] Fluid exchange occurs between the first chamber 115 and the other chamber 117, allowing gas to flow from the other chamber 117 into the first chamber 115. The flow movement between the first chamber 115 and the other chamber 117 is guided and / or restricted by the flow guiding device 123. In the illustrated embodiment, the first chamber 115 and the other chamber 117 form a sensor space surrounding the gas sensor 103.

[0108] The first gas channel 111 has a channel structure that is different from that of the second gas channel 113. Currently, the first gas channel 111 is longer than the second gas channel 113, such that the distance between one end of the first gas channel 111 and the inlet region 121 of the gas sensor 103 is shorter than the distance between one end of the second gas channel 113 and the inlet region 121 of the gas sensor 103.

[0109] Furthermore, the test unit 101 includes a first computing unit 125 configured as a control module for controlling the gas generator 105 and the gas sensor 103. For this purpose, the first computing unit 125 can be connected to the gas generator 105 and the gas sensor 103 via a communication interface, such as a cable or wireless connection. The first computing unit 125 may include one or more processors configured for corresponding or joint control of the gas generator 105 and the gas sensor 103.

[0110] To test the gas measuring instrument 100, the first computing unit 125 controls the gas generator 105 so that, during the first time period of testing by the testing unit 101, the gas generator 105 loads test gas onto the gas sensor 103 via the first gas channel 111 in a first state. During the second time period of testing, in a different state, the first computing unit 125 controls the gas generator 105 so that the gas generator loads test gas onto the gas sensor 103 via the second gas channel 113.

[0111] Because the first gas channel 111 and the second gas channel 113 differ in their channel structures, the test gas flows through the first gas channel 111 and the second gas channel 113 with different transmission characteristics.

[0112] Currently, during the first time period, the test gas is discharged at the end of the first gas channel 111, which is within a short distance of the inlet region 121 of the gas sensor 103. Accordingly, the test gas flows rapidly, i.e. directly, directly to the gas sensor 103, thereby minimizing the influence of interfering variables, such as the inflow of ambient medium from the environment or the outflow of test gas into the environment. Therefore, during the first time period, the measurement of the test gas through the gas sensor 103 in the first state is subject to a reduction in interfering variables compared to the second time period. Consequently, the measurement values ​​determined by the gas sensor 103 during the first state are particularly effective for the functionality of the gas sensor 103.

[0113] During the second time period, in another state, the test gas is discharged at the end of the second gas channel 113, which is a large distance from the sensor inlet 121 and near the space of the opening region 119.

[0114] Due to the long diffusion path associated with the long diffusion time, the measurements determined by gas sensor 103 during this second time period are particularly susceptible to interference caused by the inflow of ambient media and / or the outflow of test gas. In particular, the outflow of test gas is a significant exit path for the generated test gas, as the discharge opening of 113 is located near the opening region 119, which has a gas inlet opening. Accordingly, the measurements determined during the second time period are particularly affected by the detection of blockage in opening region 119, and the detection of blockage in opening region 119 is effective.

[0115] Accordingly, the functionality of the gas sensor 103 is tested based on the measurement values ​​determined during the first time period, and the functionality or permeability of the opening region 119 for the gas is tested based on the measurement values ​​determined during the second time period.

[0116] To analyze the measurements determined by the gas sensor 103, a second calculation unit 127 may optionally be provided in addition to the first calculation unit 125. This second calculation unit is designed as an analysis module and is communicatively connected to the gas sensor 103 via a communication interface, such as a cable or wireless interface. Of course, the first calculation unit 125 can also be used to analyze the measurements determined by the gas sensor 103.

[0117] In an embodiment not shown, a different test gas is guided through a corresponding gas channel, such as a first gas channel, during the first time period and the second time period. The two different test gases preferably differ in their diffusion coefficients, such that the transport characteristics during the first time period are different from those during the second time period due to the different test gases.

[0118] In another embodiment, only a single gas channel is provided to offer two time ranges with different transmission characteristics of the test gas. In this case, the different transmission characteristics are based on different test gas characteristics, such as different test gases used and / or different test gas temperatures used.

[0119] exist Figure 2 The diagram shows graph 200, which is plotted on its vertical axis 201 about the sensor signal in [ppm] and on its horizontal axis 203 about the time extension in [hh:mm:ss].

[0120] The change process 205 represents the measurement value determined by the gas sensor 3 during the first time period from the first gas channel 111 in the first state to supply test gas and during the period when the opening region 119 is blocked for gas, i.e., impermeable.

[0121] The change process 207 represents the measurement value determined by the gas sensor 3 during the first time period from the first gas channel 111 in the first state to supply test gas and during the period when the gas is permeable in the opening region 119, i.e., not blocked.

[0122] In addition, Figure 2 The figure shows graph 220, which is plotted on its vertical axis 221 about the sensor signal in [ppm] and on its horizontal axis 223 about the time extension in [hh:mm:ss].

[0123] The change process 225 represents the measurement value determined by the gas sensor 203 during a second time period from the second gas channel 113 in another state to test the gas supply period and during the period when the opening region 119 is blocked for gas, i.e., impermeable.

[0124] The change process 227 represents the measurement value determined by the gas sensor 103 during a second time period from the second gas channel 113 in another state to test the gas supply period and during the period when the gas is permeable to the opening region 119, i.e., unblocked.

[0125] Comparing processes 205 and 207 with processes 225 and 227, it is evident that the blockage of the opening region 119 during test gas supply via the second gas channel 113 in process 227 is significantly different from that in process 225. Furthermore, the blockage of the opening region 119 during test gas supply via the first gas channel 111 in process 205 is only negligibly different from that in process 207. Accordingly, a good distinction can be made between the blocked state of the opening region 119 and the state where the opening is permeable to gas, based on measurements determined by the gas sensor 103 during another state.

[0126] To identify a blockage, the measurement value determined by the gas sensor 103 during the second time period can be used to determine, i.e., calculate or estimate, the decay time, such as the half-value time or another value at a predetermined time point after the gas supply begins. If the difference between the decay time and a predetermined reference value is greater than a predetermined blockage threshold, it can be assumed that the opening region 119, and in particular the filter within the opening region 119, is blocked. Accordingly, for this case, the calculation unit 125 marks the gas measuring instrument 100 as blocked and stores the corresponding fault message, for example, in a fault memory.

[0127] In particular, the decay time can be calculated, for example, by the area under the maximum value between a predetermined start time and a predetermined stop time.

[0128] exist Figure 3 The diagram shows graph 300, which reproduces a unitless relative sensor signal on its vertical axis 301. This sensor signal varies due to the influence of wind at different speeds, plotted in [m / s] on the horizontal axis 303.

[0129] The change process 305 is based on the measurement value determined by the gas sensor 103 when the test gas is supplied through the second gas channel 113.

[0130] The change process 307 is based on the measurement value determined by the gas sensor 103 when the test gas is supplied through the first gas channel 111.

[0131] It is clearly evident that the distance between change process 305 and change process 307 increases with increasing wind speed. This means that the corresponding wind speed can be inferred from the distance between change process 305 and change process 307, and the device used in change process 307 is significantly less affected by the wind and is therefore more suitable for checking the sensitivity of sensor 301. This relationship can, for example, be used to disable the alarm function of gas measuring instrument 100 when a wind speed greater than a predetermined threshold is determined.

[0132] exist Figure 4 The image shows a gas measuring instrument 400.

[0133] The gas measuring instrument 400 includes a first gas channel 401, which is designed as a chamber and in which a first gas generator 403 and a computing unit 419 are arranged.

[0134] The gas measuring instrument 400 further includes a second gas passage 405, which is designed as a chamber and in which another gas generator 407 is arranged.

[0135] The first gas passage 401 comes into fluid contact with the second gas passage 405 via the gas transfer section 409, making gas exchange between the first gas passage 401 and the second gas passage 405 possible.

[0136] The second gas channel 405 comes into contact with the ambient fluid via an opening 411, making direct and immediate gas exchange between the environment and the second gas channel 405 possible. The opening serves as a sensor input and in this sense forms an opening area for the gas measuring instrument 400.

[0137] The first gas channel 401 is in contact with the sensor membrane 413, which separates the electrolyte of the gas sensor 417 of the gas measuring instrument from the first gas channel 401.

[0138] Because the first gas channel 401 does not come into direct contact with the ambient fluid, the test gas supplied by the first gas generator 403 is only minimally affected by the environmental conditions of the gas measuring instrument 400, such as wind. Accordingly, the first gas channel 401 is particularly advantageously suited for use with the test gas sensor 417.

[0139] In order to eliminate the false negative fault message that incorrectly marks the gas sensor 417 as faulty when the gas sensor 417 is measured by the first gas generator 403 to supply test gas to the internal space 415 of the sensor, the first gas generator 403 can be tested by means of another gas generator 407.

[0140] To test the first gas generator 403, it is specified that the gas sensor 417 is loaded with test gas supplied by another gas generator 407. To prevent the gas sensor 417 from being flagged as faulty when the test gas is supplied through the other gas generator 407, it is specified that the gas sensor 417 is flagged as fault-free and the first gas generator 403 is flagged as faulty. For this purpose, the calculation unit of the gas measuring instrument 400 can modify or generate a corresponding fault message in the fault memory of the gas measuring instrument 400 or in the memory of the calculation unit.

[0141] exist Figure 5 The flowchart of the introduced method 500 is shown in the figure.

[0142] Method 500 begins with step 501, which provides possible designs for the gas measuring instrument described herein. For this purpose, possible designs for, for example, the tester with a gas sensor described herein, can be connected to possible designs for the gas measuring instrument described herein.

[0143] In operation step 503, at least one gas generator of the gas measuring instrument is operated such that the gas generator supplies gas to the sensor space surrounding the gas sensor via the gas channel device with at least one test gas during the first time period of the test and during the second time period of the test.

[0144] In the determining step 505, which is performed at least sometimes in parallel with the control step 503 in time, the measured value determined by the gas sensor during a first time period and / or a second time period is determined. This can advantageously occur in such a way that the computing unit of the gas measuring instrument reads the corresponding measured value determined by the gas sensor and stores it in the working memory.

[0145] In the marking step 507, if the evaluation algorithm determines a deviation from the rated state, the gas measuring instrument is marked as faulty via test information. This marking, according to the invention, is performed by determining and outputting test information during a first time period and / or a second time period, wherein the test information indicates whether the gas measuring instrument is faulty, and wherein the determination of the test information is based on a comparison between a measured value and a predetermined gas sensor threshold, or between a determined measured value change process parameter and a predetermined change process parameter.

[0146] List of reference numerals

[0147] 100 and 400 gas measuring instruments

[0148] 101 Test Unit

[0149] 103, 417 Gas Sensors

[0150] 105 Gas Generator

[0151] 107 base

[0152] 109 Gas Channel Device

[0153] 111, 401 First Gas Passage

[0154] 113, 405 Second Gas Channel

[0155] 115 First Chamber

[0156] 117 Other chambers

[0157] 119 Opening area

[0158] 121 Entrance Area

[0159] 123 Flow Guiding Equipment

[0160] 125 First Calculation Unit

[0161] 127 Second Calculation Unit

[0162] 129 First gas discharge opening

[0163] 131 Additional gas discharge opening

[0164] 200, 220, 300 charts

[0165] 201, 221, 301 (vertical axis)

[0166] 203, 223, 303 (x-axis)

[0167] Changes in 205, 207, and 225 227, 305, 307

[0169] 403 First Gas Generator

[0170] 407 Other gas generators

[0171] 409 Gas Transfer Section

[0172] 411 Opening

[0173] 413 Sensor film

[0174] 415 Sensor Internal Space

[0175] 419 Computing Units

[0176] 500 methods

[0177] Methods and steps for 501, 503, 504, and 507

Claims

1. A gas measuring instrument (100), comprising: - At least one chemical gas sensor (103) for converting the analyte, the chemical gas sensor having a surrounding sensor space, - At least one opening region (119) forming a breathable connection between the sensor space and the environment of the gas measuring instrument, and - At least one test unit (101). The test unit (101) includes: - A gas passage device (109) having a first gas passage (111) and a second gas passage (113), and - At least one gas generator (105) configured to conduct at least one test gas into a sensor space surrounding the gas sensor (103) via the first gas channel (111) during a first time period of testing in the test unit (101), and to conduct the at least one test gas into the sensor space via the second gas channel (113) during a second time period of testing. The test gas transmission during the first time period has different transmission characteristics than during the second time period due to the structural characteristics of the corresponding gas channels (111, 113) and / or due to the test gas characteristics of the at least one test gas.

2. The gas measuring instrument (100) according to claim 1, wherein the first gas channel (111) and the second gas channel (113) are different in their channel structure.

3. The gas measuring instrument (100) according to claim 2, wherein the first gas channel opening of the first gas channel (111) is closer to the gas sensor (103) than the second gas channel opening of the second gas channel (113).

4. The gas measuring instrument (100) according to claim 2 or 3, wherein the second gas channel opening is closer to the at least one opening region (119) than the first gas channel opening.

5. The gas measuring instrument (100) according to claim 1 or 2, wherein the first gas channel (111) and the second gas channel (113) are distinguished from each other by the roughness of their inner surfaces in their channel structures.

6. The gas measuring instrument (100) according to claim 1 or 2, wherein at least one gas channel (111, 113) includes a temperature control unit configured to change the temperature inside the gas channel (111, 113) such that the test gas in the first time period is different from the test gas in the second time period in terms of its gas temperature.

7. The gas measuring instrument (100) according to claim 1 or 2, wherein the at least one gas generator (105) is configured to conduct a different test gas during the first time period through a corresponding gas channel (111, 113) than during the second time period.

8. The gas measuring instrument (100) according to claim 7, wherein the first test gas during the first time period has a different diffusion coefficient than the second test gas during the second time period.

9. The gas measuring instrument (100) according to claim 1 or 2, wherein the test is performed by the test unit (101) in at least one additional time period.

10. The gas measuring instrument (100) according to claim 1, wherein the gas measuring instrument (100) includes at least one computing unit (125) configured to receive a signal from the gas sensor (103) and thereby determine a measurement value, wherein the computing unit (125) is further configured to determine and output test information during the first time period and / or during the second time period, wherein the test information indicates whether the gas measuring instrument (100) is faulty, and wherein the determination of the test information is based on a comparison between the measurement value and a predetermined gas sensor threshold or between a determined measurement value change process parameter and a predetermined change process parameter.

11. The gas measuring instrument (100) according to claim 10, wherein the test information indicates whether the at least one opening area (119) is blocked and / or whether the gas sensor (103) is functioning properly.

12. The gas measuring instrument (100) according to claim 10 or 11, wherein the corresponding comparison performed by the calculation unit (125) depends on the determination of the measured value change process based on the decay time, mathematical derivation, statistical average, maximum value and / or integral.

13. A tester for a gas measuring instrument (100), The tester includes: - The test unit (101) of the gas measuring instrument (100) according to any one of claims 1 to 12. - An interface for reversible mechanical and / or communication connection between the test unit (101) and the gas sensor (103).

14. A test method (500) for testing a gas measuring instrument. The test method (500) includes the following steps: a) Provide a gas measuring instrument (100) according to any one of claims 1 to 12. b) Manipulate the at least one gas generator (105) such that the gas generator conducts at least one test gas into the sensor space surrounding the gas sensor (103) via the first gas channel (111) during a first time period of the test, and conducts the at least one test gas into the sensor space via the second gas channel (113) during a second time period of the test. c) Determine the measurement value determined by the gas sensor (103) during the first time period and / or during the second time period. d) Determine and output test information during the first time period and / or during the second time period, wherein the test information indicates whether the gas measuring instrument (100) is faulty, and wherein the determination of the test information is based on a comparison between the measured value or characteristic value calculated therefrom and a predetermined gas sensor threshold or a determined measured value change process parameter and a predetermined change process parameter.

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