Temperature interference compensation method based on NDIR sensor

Abstract

The invention provides a temperature interference compensation method based on an NDIR sensor. Comprising the following steps: judging the temperature change of a use environment in a preset time period, and if the temperature change of the use environment exceeds a set first temperature threshold value, setting a heat preservation device for an NDIR sensor; the temperature value of the current use environment is obtained, if the temperature value of the current use environment is larger than a second temperature threshold value, the NDIR sensor is subjected to self-heating, and otherwise, the NDIR sensor is subjected to external heating; when the temperature of the NDIR sensor reaches the target temperature, external heating is stopped, measurement is started, meanwhile, whether the temperature of the NDIR sensor continues to rise and exceeds the target temperature by a set value or not is judged, and if yes, the measurement result of the NDIR sensor is compensated. The problem that in the prior art, due to the fact that an NDIR sensor is affected by temperature changes, the measurement result is inaccurate is solved.

Description

Technical Field

[0001] The present application relates to the field of gas detection technology, and in particular to a temperature interference compensation method based on an NDIR sensor. Background Art

[0002] NDIR (Non-Dispersive InfraRed) technology is a method based on gas absorption theory. The principle of using NDIR sensors to measure the concentration of the gas to be measured is that after the radiation emitted by the infrared light source is absorbed by a certain concentration of the gas to be measured, the spectral intensity of the radiation light will change, and the concentration of the gas to be measured can be calculated based on the change in spectral intensity.

[0003] At present, most NDIR sensors on the market are easily affected by temperature changes when in use, resulting in deviations in the measurement of gas concentration. Therefore, a method is needed to compensate for the temperature interference of NDIR sensors. Summary of the invention

[0004] The present application provides a temperature interference compensation method based on an NDIR sensor, which can solve the problem in the prior art that the NDIR sensor is affected by temperature changes, resulting in inaccurate measurement results.

[0005] The temperature interference compensation method based on NDIR sensor provided in this application includes: S11: judging the change of the use environment temperature within a preset time period, and if the change of the use environment temperature exceeds a set first temperature threshold, setting a heat preservation device for the NDIR sensor; S12: Acquire the temperature value of the current use environment. If the temperature value of the current use environment is greater than the second temperature threshold, the NDIR sensor is self-heated; otherwise, the NDIR sensor is externally heated. S13: When the temperature of the NDIR sensor reaches the target temperature, the external heating is stopped and the measurement is started. At the same time, it is determined whether the temperature of the NDIR sensor continues to rise and exceeds the target temperature-a set value. If so, the measurement result of the NDIR sensor is compensated.

[0006] In some embodiments, when the preset time period is one year, the corresponding first temperature threshold is 15°C; when the preset time period is one month, the corresponding first temperature threshold is 5°C.

[0007] In some embodiments, the heat preservation device is heat preservation cotton, which is arranged on the NDIR sensor by covering.

[0008] In some embodiments, the first temperature sensor is used to collect the temperature of the use environment within a preset time period and the temperature value of the current use environment; and the second temperature sensor is used to collect the temperature of the NDIR sensor.

[0009] In some embodiments, the second temperature threshold value ranges from 25°C to 30°C.

[0010] In some embodiments, the self-heating of the NDIR sensor is heating by utilizing the heat of the circuit when the NDIR sensor is working.

[0011] In some embodiments, the target temperature ranges from 40°C to 45°C.

[0012] In some embodiments, further, the set value exceeding the target temperature has a value ranging from 2°C to 5°C.

[0013] In some embodiments, the measurement results of the NDIR sensor are compensated by the following formula: , in, is the gas concentration after compensation, is the gas concentration measured by the NDIR sensor, is the temperature of the NDIR sensor collected by the second temperature sensor, is the target temperature, is a constant.

[0014] The temperature interference compensation method based on the NDIR sensor provided in the present application can add a heat preservation device to the NDIR sensor when the ambient temperature is unstable, provide external heating to the NDIR sensor when the ambient temperature is low, and compensate for the gas concentration measured by the NDIR sensor when the temperature of the heated NDIR sensor has a large overshoot, thereby effectively solving the problem in the prior art that the NDIR sensor is affected by temperature changes, resulting in inaccurate measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of a flow chart of a temperature interference compensation method based on an NDIR sensor provided in an embodiment of the present application; Figure 2 A schematic diagram of the installation position of an NDIR sensor and a heat preservation device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0016] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0017] NDIR sensors are used in many gas measuring instruments, but many factors in NDIR sensors, such as light source spectrum, detector, filter temperature coefficient, operational amplifier temperature coefficient, resistor and capacitor temperature coefficient, are easily affected by temperature, which results in that the measurement accuracy of NDIR sensors is greatly affected by temperature. Therefore, the purpose of this application is to provide a method for compensating for temperature interference of NDIR sensors.

[0018] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0019] like Figure 1 As shown, a temperature interference compensation method based on an NDIR sensor provided in an embodiment of the present application includes: S11: judging the change of the use environment temperature within a preset time period, and if the change of the use environment temperature exceeds a set first temperature threshold, setting a heat preservation device for the NDIR sensor.

[0020] In the embodiment of the present application, for example, the preset time period can be one year or one month. When the preset time period is one year, the corresponding first temperature threshold is 15° C.; when the preset time period is one month, the corresponding first temperature threshold is 5° C. The above preset time period and first temperature threshold are only examples, and those skilled in the art can set them as needed.

[0021] In the embodiment of the present application, by judging the change of the ambient temperature within a preset time period, the stability of the ambient temperature can be clearly determined. When the stability of the ambient temperature is high, that is, there is no large temperature fluctuation, there is no need to add a heat preservation device; when the stability of the ambient temperature is low, that is, there is a large temperature fluctuation, it is necessary to add a heat preservation device to keep the NDIR sensor warm, thereby ensuring the stability of the working environment temperature of the NDIR sensor.

[0022] In the embodiment of the present application, the heat preservation device may be heat preservation cotton, preferably, EVA foam cotton, but the embodiment of the present application does not limit the specific material of the heat preservation cotton; in addition, the thickness of the heat preservation cotton can be adjusted according to different NDIR sensors. Figure 2 As shown, the heat preservation device can be arranged on the NDIR sensor in a covering manner.

[0023] S12: Obtaining the temperature value of the current use environment. If the temperature value of the current use environment is greater than the second temperature threshold, the NDIR sensor is self-heated. Otherwise, the NDIR sensor is externally heated.

[0024] In the embodiment of the present application, the value range of the second temperature threshold may be 25° C. to 30° C. In the embodiment of the present application, those skilled in the art may also select the value range and specific value of the second temperature threshold as required.

[0025] In the embodiment of the present application, the self-heating of the NDIR sensor is heating by utilizing the heat of the circuit when the NDIR sensor is working. Since the circuit of the NDIR sensor has a self-heating effect when it is running, the sensor is heated by utilizing the heat of the circuit when the NDIR sensor is working.

[0026] In the embodiment of the present application, the external heating may be performed by attaching a heating film to the NDIR sensor, thereby heating the NDIR sensor. However, the present application does not limit the specific method of the external heating.

[0027] In the embodiment of the present application, the first temperature sensor can be used to collect the temperature of the use environment within a preset time period and the temperature value of the current use environment. After the temperature information collected by the first temperature sensor is transmitted to the processor, the processor controls whether to set a heating device and whether to perform external heating according to the judgment logic shown in step S11 and step S12, and outputs the control information to the external actuator.

[0028] In the embodiment of the present application, by setting the temperature value of the current use environment to be greater than the second temperature threshold, that is, when the temperature value of the use environment is high and belongs to the high temperature condition, the NDIR sensor is used for self-heating, and when the temperature value of the current use environment is not greater than the second temperature threshold, that is, when the temperature of the use environment does not belong to the high temperature condition, the NDIR sensor is heated by external heating. On the one hand, the heating efficiency can be effectively improved when the ambient temperature is low, and on the other hand, the power consumption of heating can be effectively reduced when the ambient temperature is high.

[0029] S13: When the temperature of the NDIR sensor reaches the target temperature, the external heating is stopped and the measurement is started. At the same time, it is determined whether the temperature of the NDIR sensor continues to rise and exceeds the target temperature-a set value. If so, the measurement result of the NDIR sensor is compensated.

[0030] In the embodiment of the present application, it is possible to set up a second temperature sensor to collect the temperature of the NDIR sensor.

[0031] In the embodiment of the present application, the target temperature may be in the range of 40° C. to 45° C. However, the embodiment of the present application does not limit the target temperature range and specific value, and those skilled in the art may set it as needed.

[0032] In an embodiment of the present application, when the temperature value of the current use environment is not greater than the second temperature threshold, that is, when external heating is adopted, due to the influence of heating inertia, after the external heating is stopped, the temperature of the NDIR sensor is likely to continue to rise. If the temperature of the NDIR sensor exceeds the target temperature-a set value, which can be a value between 2°C and 5°C in the embodiment of the present application, it will have a greater impact on the measurement result of the NDIR sensor, for example, it will make the measurement result of the NDIR sensor lower, so the measurement result needs to be compensated.

[0033] In an embodiment of the present application, when the temperature value of the current use environment is greater than the second temperature threshold, that is, when self-heating is adopted, due to the influence of the higher external use environment temperature and the inertia of self-heating, after reaching the target temperature, the temperature of the NDIR sensor is likely to continue to rise. If the temperature of the NDIR sensor exceeds the target temperature by a set value, which can be a value between 2°C and 5°C in the embodiment of the present application, it will have a greater impact on the measurement result of the NDIR sensor, for example, it will make the measurement result of the NDIR sensor lower, so the measurement result needs to be compensated.

[0034] In the embodiment of the present application, the value range of the set value exceeding the target temperature can be 2°C~5°C, but the embodiment of the present application does not limit the value range and specific value, and technicians in this field can set it as needed.

[0035] In the embodiment of the present application, the measurement result of the NDIR sensor can be compensated by the following formula: , in, is the gas concentration after compensation, is the gas concentration measured by the NDIR sensor, is the temperature of the NDIR sensor collected by the second temperature sensor, is the target temperature, is a constant.

[0036] In the present application embodiment, the constant The value range of can be between 0 and 0.005, but the embodiment of the present application does not limit its value, and those skilled in the art can select or set a suitable value as needed.

[0037] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit "first", "second" and "third" to different types.

[0038] In the description of the embodiments of the present application, "exemplary", "for example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary", "for example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "for example" or "for example" is intended to present related concepts in a specific way.

[0039] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; the “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0040] In some processes described in the embodiments of the present application, multiple operations or steps that appear in a specific order are included, but it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or in parallel, and the sequence number of the operation is only used to distinguish the different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed in sequence or in parallel, and these operations or steps may be combined.

[0041] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A temperature disturbance compensation method based on NDIR sensor, characterized in that: The compensation method includes: S11: judging the change of the use environment temperature within a preset time period, and if the change of the use environment temperature exceeds a set first temperature threshold, setting a heat preservation device for the NDIR sensor; S12: Acquire the temperature value of the current use environment. If the temperature value of the current use environment is greater than the second temperature threshold, the NDIR sensor is self-heated; otherwise, the NDIR sensor is externally heated. S13: When the temperature of the NDIR sensor reaches the target temperature, the external heating is stopped and the measurement is started. At the same time, it is determined whether the temperature of the NDIR sensor continues to rise and exceeds the target temperature-a set value. If so, the measurement result of the NDIR sensor is compensated.

2. The temperature disturbance compensation method according to claim 1, characterized in that: When the preset time period is one year, the corresponding first temperature threshold is 15°C; when the preset time period is one month, the corresponding first temperature threshold is 5°C.

3. The temperature disturbance compensation method according to claim 1, characterized in that: The heat preservation device is heat preservation cotton, which is arranged on the NDIR sensor in a covering manner.

4. The temperature disturbance compensation method according to claim 1, characterized in that: The first temperature sensor is used to collect the temperature of the use environment within a preset time period and the temperature value of the current use environment; the second temperature sensor is used to collect the temperature of the NDIR sensor.

5. The temperature disturbance compensation method according to claim 1, characterized in that: The second temperature threshold value ranges from 25°C to 30°C.

6. The temperature disturbance compensation method according to claim 1, characterized in that: The self-heating of the NDIR sensor is heating by utilizing the heat of the circuit when the NDIR sensor is working.

7. The temperature disturbance compensation method according to claim 7, characterized in that: The target temperature ranges from 40°C to 45°C.

8. The temperature disturbance compensation method according to claim 1, characterized in that: The set value exceeding the target temperature ranges from 2°C to 5°C.

9. The temperature disturbance compensation method according to claim 1, characterized in that: The measurement results of the NDIR sensor are compensated by the following formula: ， in, is the gas concentration after compensation, is the gas concentration measured by the NDIR sensor, is the temperature of the NDIR sensor collected by the second temperature sensor, is the target temperature, is a constant.

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