CN115372418A

CN115372418A - Gas sensor testing and calibrating method and system and electronic equipment

Info

Publication number: CN115372418A
Application number: CN202210970070.4A
Authority: CN
Inventors: 闫立琼
Original assignee: Lumi United Technology Co Ltd
Current assignee: Lumi United Technology Co Ltd
Priority date: 2022-08-12
Filing date: 2022-08-12
Publication date: 2022-11-22

Abstract

The application relates to a method, a system, an electronic device and a storage medium for testing and calibrating a gas sensor. The method comprises the following steps: acquiring a detection value measured by a gas sensor at each of a plurality of gas concentrations; comparing the detection value under each gas concentration with the standard value under the gas concentration to judge whether the gas sensor reaches the preset standard or not; if the gas sensor is judged not to reach the preset standard, calibrating the gas sensor; acquiring a calibration detection value of the calibrated gas sensor measured at each of the plurality of gas concentrations; and comparing the calibration detection value under each gas concentration with the standard value under the gas concentration to judge whether the calibrated gas sensor reaches the preset standard or not. By adopting the method, the standard reaching rate of the gas sensor can be improved, and the loss of products which do not reach the standard and are caused by error detection can be effectively reduced.

Description

Gas sensor testing and calibrating method and system and electronic equipment

Technical Field

The invention relates to the technical field of sensors, in particular to a method, a system and electronic equipment for testing and calibrating a gas sensor.

Background

Gas sensors can be used to detect the concentration of certain substances in the air, such as the concentration of TVOC (Total Volatile Organic Compounds), nitrides, PM2.5, and the like. Most gas sensors use semiconductor gas sensors to detect the concentration of substances in the air, which convert the relevant information into electrical signals to facilitate detection, analysis and alarm of the detected gas. When the detected gas exists in the ambient air, the conductivity of the gas sensor changes, the higher the concentration of the detected gas is, the higher the conductivity of the gas sensor is, and the corresponding electric signal is amplified through a proper amplifying circuit and then can be converted into a gas concentration detection value.

However, different gas sensor individuals of the same type may have differences in sampling accuracy due to process reasons or other environmental reasons such as high temperature, high humidity, etc., thereby causing the gas concentration detected by some gas sensors to be inaccurate and the detection accuracy to be not up to standard. How to improve the standard-reaching rate of the gas sensor and reduce the loss of products which do not reach the standard is a very important technical problem in industrial production.

Disclosure of Invention

In view of the above, there is a need to provide a method, a system, an electronic device and a storage medium for testing and calibrating a gas sensor, which can improve the compliance rate of the gas sensor and reduce the loss of substandard products.

A method of testing and calibrating a gas sensor, comprising:

acquiring a detection value measured by a gas sensor at each of a plurality of gas concentrations;

comparing the detection value under each gas concentration with the standard value under the gas concentration to judge whether the gas sensor reaches the preset standard or not;

if the gas sensor is judged not to reach the preset standard, calibrating the gas sensor;

acquiring a calibration detection value of the calibrated gas sensor measured at each of the plurality of gas concentrations;

and comparing the calibration detection value under each gas concentration with the standard value under the gas concentration to judge whether the calibrated gas sensor reaches the preset standard or not.

A test and calibration system for a gas sensor, comprising:

the concentration adjusting device is used for adjusting the gas concentration in the environment;

the controller is connected with the gas sensor and the concentration adjusting device and is used for controlling the concentration adjusting device to work so as to change the gas concentration in the environment, acquiring a detection value of the gas sensor under each gas concentration in a plurality of gas concentrations, comparing the detection value under each gas concentration with a standard value under the gas concentration so as to judge whether the gas sensor reaches a preset standard or not, and calibrating the gas sensor if the gas sensor does not reach the preset standard; and controlling the concentration adjusting device to work so as to change the gas concentration in the environment, acquiring a calibration detection value of the calibrated gas sensor at each gas concentration in the plurality of gas concentrations, and comparing the calibration detection value at each gas concentration with a standard value at the gas concentration to judge whether the calibrated gas sensor reaches a preset standard.

An electronic device comprising a memory storing a computer program and a processor implementing the steps in the method for testing and calibrating a gas sensor according to embodiments of the present application when the computer program is executed.

A computer-readable storage medium having stored thereon a program executable by a processor to perform steps in a method for testing and calibrating a gas sensor according to embodiments of the present application.

According to the method, the system, the electronic equipment and the storage medium for testing and calibrating the gas sensor, the gas sensor is tested under a plurality of gas concentrations, and the detected value measured under each gas concentration is compared with the standard value under the gas concentration to judge whether the gas sensor reaches the preset standard, so that the accuracy is higher compared with that of single test, and the misdetection rate is reduced; the gas sensor which does not reach the preset standard is not directly eliminated, but is calibrated, and then the gas sensor is tested again to judge whether the calibrated gas sensor reaches the preset standard, so that the detection precision of the gas sensor is improved, the standard reaching rate is improved, and the loss of products which do not reach the standard and are caused by misdetection is effectively reduced.

Drawings

FIG. 1 is a block diagram of a system for testing and calibrating a gas sensor according to an embodiment;

FIG. 2 is a block diagram of a system for testing and calibrating a gas sensor according to another embodiment;

FIG. 3 is a block diagram showing a test and calibration system for a gas sensor according to still another embodiment;

FIG. 4 is a flow chart of a method for testing and calibrating a gas sensor in one embodiment;

FIG. 5 is a flow chart illustrating an embodiment of determining whether a gas sensor meets predetermined criteria;

FIG. 6 is a flow chart illustrating the process of determining whether the gas sensor meets the predetermined criteria in another embodiment;

fig. 7 is a schematic diagram of an apparatus for a test and calibration system for TVOC sensors in one embodiment;

FIG. 8 is a block diagram of a test and calibration system for a TVOC sensor in one embodiment;

fig. 9 is a block diagram of a testing and calibration system for TVOC sensors in another embodiment;

fig. 10 is a flow chart of a method for testing and calibrating a TVOC sensor according to an embodiment.

Detailed Description

The present invention will be described in further detail with reference to the following detailed description and accompanying drawings. Wherein like elements in different embodiments are numbered with like associated elements. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

The numbering of the components as such, e.g., "first", "second", etc., is used herein only to distinguish the objects as described, and does not have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings).

The application provides a test and calibration system and method of a gas sensor, the system and method can be applied to the production field test scene of the gas sensor, namely for the gas sensor manufactured and molded on the production line or the PCBA (Printed Circuit Board) equipped with the gas sensor, equipment and the like, the system and method is used for testing whether the gas sensor reaches the factory standard, and calibrating the gas sensor which does not reach the factory standard; the system and method may also be used to test for compliance with usage requirements and to calibrate for non-compliance during routine use of the gas sensor or a PCBA, appliance or the like fitted with the gas sensor. Wherein the gas sensor refers to a sensor for detecting the concentration of one or more substances in the air, and may specifically be a TVOC sensor, a smoke sensor, a PM2.5 sensor, etc.

Referring to fig. 1, one embodiment provides a system for testing and calibrating a gas sensor, which includes a concentration adjustment device 10 and a controller 20, which are described below.

The concentration adjusting device 10 is used to adjust the gas concentration in the environment. For example, the concentration adjustment device 10 may increase or decrease the gas concentration.

The gas concentration refers to the concentration of the detection object of the gas sensor in the air. The user can adopt corresponding material simulation to be surveyed gas according to gas sensor's measuring thing, for example to TVOC sensor, smoke transducer, can use alcohol simulation to be surveyed gas, then concentration adjusting device 10 is arranged in adjusting the alcohol concentration in the air, and to PM2.5 sensor, can use dust simulation to be surveyed gas, then concentration adjusting device 10 is arranged in adjusting the dust concentration in the air.

The concentration adjusting device 10 can heat, atomize, liquefy, etc. the material to increase the gas concentration, and specifically can be determined according to the form of the material detected by the gas sensor, for example, the sensor for detecting solid particles can adopt an atomizing mode, and the sensor for detecting liquid molecules can adopt a liquefying mode. The concentration adjusting device 10 can reduce the gas concentration by ventilation, air purification, or the like.

The controller 20 is connected to the gas sensor and the concentration adjusting apparatus 10, and is configured to control the concentration adjusting apparatus 10 to operate to change the gas concentration in the environment, obtain a detection value of the gas sensor at each of a plurality of gas concentrations, compare the detection value at each gas concentration with a standard value at the gas concentration, so as to determine whether the gas sensor reaches a preset standard, and calibrate the gas sensor if it is determined that the gas sensor does not reach the preset standard; the concentration adjusting device 10 is controlled to work to change the gas concentration in the environment, obtain a calibration detection value of the calibrated gas sensor at each of the plurality of gas concentrations, and compare the calibration detection value at each gas concentration with a standard value at the gas concentration to determine whether the calibrated gas sensor reaches a preset standard.

Specifically, the controller 20 may control the concentration adjustment device 10 to operate through serial/parallel communication, such as UART (Universal Asynchronous Receiver/Transmitter) communication, and obtain a detection value measured by the gas sensor, such as I ² C communication, etc.

The Controller 20 may be a CPU (Central Processing Unit), an MCU (Micro Controller Unit), an industrial personal computer, or the like, or a combination thereof. In one embodiment, the controller 20 may include an upper computer and a lower computer, the upper computer may be a CPU, an MCU, or the like, and the lower computer may be a desktop computer, a notebook computer, an industrial personal computer, or the like. The upper computer is provided with an operating system and test software, and a user can use the upper computer to operate the test and calibration system of the gas sensor and check the test result. The lower computer receives the instruction sent by the upper computer, controls the concentration adjusting device 10 to work so as to adjust the gas concentration in the environment, obtains the detection value of the gas sensor and sends the detection value to the upper computer, the upper computer compares the calibration detection value under each gas concentration with the standard value under the gas concentration, judges whether the calibrated gas sensor reaches the preset standard or not, and displays the judgment result. The communication mode between the upper computer and the lower computer can be bus communication, such as USB communication.

When testing and calibrating the gas sensor, the controller 20 controls the concentration adjustment device 10 to work to change the gas concentration in the environment to form different gas concentration environments, for example, the gas concentration in the environment is changed through multiple increasing and/or decreasing operations, at each gas concentration, the controller 20 obtains the detection value measured by the gas sensor, and compares the detection value at each gas concentration with the standard value at the gas concentration to determine whether the gas sensor reaches the preset standard.

The standard value is a value to be regarded as an accurate value of the gas concentration as a judgment reference, and may be a value specified in advance or a detection result of a standard instrument. The detected value of the gas sensor can be compared with a standard value to determine whether the gas sensor meets the preset standard, for example, the controller 20 can calculate the difference between the detected value at each gas concentration and the standard value at the gas concentration, and determine whether the gas sensor meets the preset standard according to the difference. The controller 20 determines whether the gas sensor meets the predetermined standard by determining whether the detection accuracy of the gas sensor meets a predetermined requirement, wherein the detection accuracy is obtained by comparing the detection value of the gas sensor with a standard value, for example, the detection accuracy may be represented by a difference between the detection value and the standard value, and the controller 20 determines whether the gas sensor meets the predetermined standard, specifically, whether the difference between the detection value and the standard value is within a predetermined interval. The preset standard can be set according to actual needs.

When the controller 20 performs the judgment, the controller may perform the judgment once after controlling the concentration adjustment device 10 to adjust the gas concentration each time, and when the gas sensor is judged not to reach the preset standard, the controller does not adjust the gas concentration any more to perform the next judgment, otherwise, the controller continues to adjust the gas concentration to perform the judgment until the preset times is reached; or the concentration adjusting device 10 may be controlled to adjust for a preset number of times, the comparison result between the detection value of the gas sensor and the standard value at each gas concentration is stored, and finally whether the gas sensor reaches the preset standard or not is judged according to all the comparison results.

The gas sensor is calibrated if the controller 20 determines that the gas sensor does not meet the predetermined criteria. Specifically, the calibration may be performed by adjusting the detection value of the gas sensor at a certain gas concentration to a standard value at the gas concentration, or by adjusting the detection value of a plurality of gas sensors in the same batch to an average value of the detection values at the gas concentration. The gas sensor can also be calibrated in a compensation mode, and a compensation value is written into the gas sensor, so that the gas sensor can output the detection value after adding or subtracting the compensation value during each detection.

After calibration, the controller 20 controls the concentration adjustment device 10 to operate to change the gas concentration in the environment, obtain a calibration detection value of the calibrated gas sensor at each of the plurality of gas concentrations, and compare the calibration detection value at each gas concentration with a standard value at the gas concentration to determine whether the calibrated gas sensor reaches a preset standard. For the specific procedure of the test, reference may be made to the test procedure before calibration, and details thereof are not repeated herein. And after calibration, the gas sensor is tested again, whether the gas sensor reaches the preset standard is judged, the effectiveness of calibration can be checked, if the gas sensor does not reach the preset standard, the gas sensor can be eliminated, and if the gas sensor reaches the preset standard, the gas sensor can be normally used.

In the embodiment, the test and calibration system of the gas sensor tests the gas sensor under a plurality of gas concentrations, and compares the detected value under each gas concentration with the standard value under the gas concentration to judge whether the gas sensor reaches the preset standard, so that the accuracy is higher compared with that of a single test, and the false detection rate is reduced; the gas sensor which does not reach the preset standard is not directly eliminated, but is calibrated, and then testing is carried out again to judge whether the calibrated gas sensor reaches the preset standard or not, so that the detection precision of the gas sensor is improved, the standard reaching rate is improved, and the loss of products which do not reach the standard and are caused by error detection is effectively reduced.

In one embodiment, the gas sensor that meets the predetermined standard may be a good product, and the gas sensor that does not meet the predetermined standard may be further divided into an undetermined product and a defective product, wherein the defective product has a larger difference from the undetermined product to the predetermined standard. The controller 20 determines whether the gas sensor meets the predetermined standard, including determining whether the gas sensor is a good product, a defective product, or an undetermined product, and further, if the controller 20 determines that the gas sensor does not meet the predetermined standard, calibrating the gas sensor specifically includes: and if the gas sensor is judged to be the undetermined product, calibrating the gas sensor. The products to be determined can be considered to have calibration conditions and still reach the preset standard through calibration, and the defective products can be considered to have overlarge difference with the preset standard and cannot be corrected through calibration, so that the products are not calibrated any more.

In this embodiment, the gas sensor that does not reach the preset standard is further divided into an undetermined product and a defective product, the defective product has a larger difference from the undetermined product to the preset standard, and only the undetermined product is calibrated, while the defective product is not calibrated any more because of the overlarge difference from the preset standard, so that invalid calibration can be reduced, and the efficiency of testing and calibrating the gas sensor is improved.

On the basis of the above embodiment, the controller 20 controls the concentration adjustment device 10 to operate to change the gas concentration in the environment, obtain the detection value of the gas sensor at each of the plurality of gas concentrations, and compare the detection value at each gas concentration with the standard value at the gas concentration to determine whether the gas sensor reaches the preset standard, which may specifically include the following processes: controlling the concentration adjusting device 10 to work for a first preset time so that the concentration of the gas in the environment is a first gas concentration; acquiring a first detection value measured by a gas sensor under a first gas concentration; judging whether the difference value between the first detection value and the first standard value is within a first preset interval, if so, judging that the gas sensor is good, otherwise, controlling the concentration adjusting device 10 to work for a second preset time so that the gas concentration in the environment is a second gas concentration, and acquiring a second detection value measured by the gas sensor under the second gas concentration; and judging whether the difference value between the second detection value and the second standard value is within a second preset interval, if so, judging that the gas sensor is a pending product, and otherwise, judging that the gas sensor is a defective product.

Wherein the first standard value and the second standard value are respectively a standard value under the first gas concentration and a standard value under the second gas concentration. The change in the gas concentration may be a decrease and then increase or increase (i.e., the first gas concentration is less than the second gas concentration), or may be an increase and then decrease or decrease (i.e., the first gas concentration is greater than the second gas concentration), which is not limited herein. The working time of the concentration adjusting apparatus 10 can be set according to the measurement requirement, for example, it is required to test the performance of the gas sensor when the gas concentration is close to 0, the controller 20 should control the concentration adjusting apparatus 10 to reduce the gas concentration, and work for a longer time to make the gas concentration close to 0 as much as possible, and if the gas concentration is required to be increased all the time and the difference between the first gas concentration and the second gas concentration is larger, the second preset time should be longer, and if the difference between the first gas concentration and the second gas concentration is required to be smaller, the second preset time should be shorter.

The difference between the detection value and the standard value may be the value obtained by subtracting the standard value from the detection value, or may be the value obtained by subtracting the standard value from the detection value. The controller 20 determines whether the gas sensor meets the predetermined standard according to whether the difference is within a predetermined interval. For example, for the TVOC sensor, the first preset interval and the second preset interval may be set to [ -10,10] or an interval smaller than [ -10,10], and when the gas concentration is small, the difference between the detection value and the standard value should be small, and thus, the interval may be set smaller than [ -10,10 ].

The embodiment adopts a sectional test mode, firstly tests the gas sensor under the first gas concentration, if the gas sensor is good, the subsequent steps are not carried out, if the gas sensor is not good, the gas sensor is further tested under the second gas concentration, and whether the gas sensor is a pending product or a defective product is judged, so that the probability that the gas sensor is misjudged as the defective product is reduced, and the loss is reduced.

On the basis of the above embodiment, the controller 20 may calibrate the gas sensor to obtain a compensation value according to a difference between the second detection value and the second standard value, and write the compensation value into the gas sensor.

Specifically, if the second detection value X2 is smaller than the second standard value Y2, the compensation value C2= | X2-Y2|, and if the second detection value X2 is larger than the second standard value Y2, the compensation value C2= - | X2-Y2|, and the controller 20 writes the compensation value C2 into the gas sensor, so that the gas sensor outputs the detection value after adding the compensation value C2 to the detection value at each detection. When the controller 20 writes the compensation values, the compensation values may be written to the MCU on its PCBA for the gas sensors already mounted on the PCBA.

In the embodiment, the compensation mode is adopted for calibration, the compensation value is obtained according to the difference value between the second detection value and the second standard value, and the compensation value is written into the gas sensor, so that the gas sensor outputs the detection value after adding the compensation value to the detection value in each detection, the calibration is not required to be carried out under each gas concentration, the adaptability is wide, the deviation between the detection value and the standard value is reduced through the compensation, and the detection precision of the gas sensor is improved.

In one embodiment, the controller 20 controls the concentration adjusting device to operate to change the gas concentration in the environment, obtain a calibration detection value of the calibrated gas sensor at each of the plurality of gas concentrations, and compare the calibration detection value at each gas concentration with a standard value at the gas concentration to determine whether the calibrated gas sensor reaches a preset standard, which may specifically include the following processes: controlling the concentration adjusting device 10 to work for a third preset time, so that the gas concentration in the environment is a third gas concentration; acquiring a third detection value measured by the calibrated gas sensor under a third gas concentration; judging whether the difference value between the third detection value and a third standard value is within a third preset interval, if not, judging that the gas sensor does not reach a preset standard, if so, controlling the concentration regulating device 10 to work for a fourth preset time so that the gas concentration in the environment is a fourth gas concentration, and acquiring a fourth detection value measured by the gas sensor under the fourth gas concentration; and judging whether the difference value of the fourth detection value and the fourth standard value is within a fourth preset interval, if so, judging that the gas sensor reaches a preset standard, and otherwise, judging that the gas sensor does not reach the preset standard.

The determination that the gas sensor meets the preset standard may specifically be determination that the gas sensor is a good product, and the determination that the gas sensor does not meet the preset standard may specifically be determination that the gas sensor is a defective product.

The third standard value and the fourth standard value are respectively a standard value under the third gas concentration and a standard value under the fourth gas concentration. Likewise, the change of the gas concentration may be decreased first and then increased or increased all the time (i.e., the third gas concentration is less than the fourth gas concentration), or may be increased first and then decreased or decreased all the time (i.e., the third gas concentration is greater than the fourth gas concentration), which is not limited herein. The working time of the concentration adjusting device 10 can be set according to the measurement requirement, for example, the performance of the gas sensor when the gas concentration is close to 0 needs to be tested, the controller 20 should control the concentration adjusting device 10 to reduce the gas concentration, and work for a longer time to make the gas concentration close to 0 as much as possible, and as for a fourth preset time, if the gas concentration is required to be increased all the time, and the difference between the third gas concentration and the fourth gas concentration is larger, the fourth preset time should be longer, and if the difference between the third gas concentration and the fourth gas concentration is required to be smaller, the fourth preset time should be shorter.

The difference between the calibration detection value and the standard value may be the calibration detection value minus the standard value, or the standard value minus the calibration detection value. The controller 20 determines whether the calibrated gas sensor meets a predetermined standard according to whether the difference is within a predetermined interval. It can be understood that the difference between the calibration detection value and the standard value should be smaller than the difference between the detection value and the standard value before calibration, and therefore the third preset interval and the fourth preset interval should be smaller than the second preset interval to ensure the validity of calibration. The third and fourth preset intervals may be set according to the gas type and gas concentration, for example, for a TVOC sensor, if the second preset interval is [ -10,10], the third and fourth preset intervals may be [ -5,5] or a smaller interval than [ -5,5 ].

The embodiment adopts a sectional test mode, firstly, the calibrated gas sensor is tested under the third gas concentration, if the gas sensor still does not reach the preset standard, the subsequent steps are not carried out, thereby reducing the unnecessary test times and improving the test efficiency.

Referring to fig. 2, the concentration adjusting device 10 in one embodiment includes a concentration increasing device 11 and a concentration decreasing device 12. The concentration increasing means 11 is used for increasing the concentration of the gas in the environment, and may include a nebulizer, a liquefier, and/or an alcohol burner, etc., which may be determined from the material simulating the gas to be measured. The concentration reducing means 12 is used for reducing the concentration of gases in the environment and may comprise ventilation equipment and/or fans etc.

On the basis of the above embodiment, the controller 20 may be specifically configured to control the concentration reducing device 12 to operate for a first preset time, control the concentration increasing device 11 to operate for a second preset time, control the concentration increasing device 11 to operate for a third preset time, and control the concentration reducing device 12 to operate for a fourth preset time, so that the gas concentration generally tends to increase first and then decrease.

It can be understood that if the gas concentration is increased and decreased for multiple times, the consumed materials and time are more, and in the embodiment, the gas concentration is increased first and then decreased, so that the material usage amount and the test and calibration time can be saved.

Referring to fig. 3, the testing and calibrating system for gas sensor in one embodiment further includes an air quality detector 30, and the detection results of the air quality detector 30 at different gas concentrations are used as standard values at the corresponding gas concentrations.

In the present embodiment, using the air quality detector 30 as a standard instrument, the air quality detector 30 can detect the gas concentration in the air, and the detection result of the air quality detector 30 at each gas concentration is used as a standard value at the gas concentration for comparison with the detection value of the gas sensor, for example, the detection result of the air quality detector 30 at a first gas concentration is used as a first standard value. The air quality detector 30 should be the same as the detected object of the detected gas sensor in type, and an air quality detector with a relatively accurate detection result is adopted, for example, the air quality detector which is just delivered from the factory can be used as a standard instrument, and the air quality detector is subjected to point inspection and verification in a fixed period, so as to ensure the accuracy of the standard value.

In this embodiment, the controller 20 may specifically be configured to: acquiring a first detection value of the gas sensor under the first gas concentration, acquiring a detection result of the air quality detector 30 under the first gas concentration as a first standard value, and judging whether a difference value between the first detection value and the first standard value is within a first preset interval; acquiring a second detection value measured by the gas sensor under the second gas concentration, acquiring a detection result of the air quality detector 30 under the second gas concentration as a second standard value, and judging whether a difference value between the second detection value and the second standard value is within a second preset interval; acquiring a third detection value of the calibrated gas sensor at a third gas concentration, acquiring a detection result of the air quality detector 30 at the third gas concentration as a third standard value, and judging whether a difference value between the third detection value and the third standard value is within a third preset interval; and acquiring a fourth detection value measured by the calibrated gas sensor under the fourth gas concentration, acquiring a detection result of the air quality detector 30 under the fourth gas concentration as a fourth standard value, and judging whether a difference value between the fourth detection value and the fourth standard value is within a fourth preset interval. The controller 20 may acquire the detection result of the air quality detector 30 through serial/parallel communication, such as UART communication.

In this embodiment, the air quality detector is used as a standard instrument, and the detection result of the air quality detector on the gas concentration is used as a standard value, so that a more accurate standard value can be obtained, and the implementation is simpler, and the detection result of the air quality detector on the gas concentration can be used as a standard value in the test process of different batches of gas sensors, so that the consistency of the gas sensors is improved.

The present application also provides a testing and calibrating method for a gas sensor, which is applicable to the testing and calibrating system for a gas sensor, and particularly applicable to the controller 20. As shown in FIG. 4, one embodiment of the method includes steps 410-450, which are described in detail below with respect to the method applied to the controller 20 of FIG. 1.

Step 410: a detection value measured by the gas sensor at each of the plurality of gas concentrations is acquired.

The gas concentration refers to the concentration of the detection object of the gas sensor in the air. The user can adopt corresponding material simulation to be surveyed gas according to the detection thing of gas sensor, and then gas concentration is the concentration of this simulant in the test procedure. For example, for a TVOC sensor or a smoke sensor, the gas concentration is the alcohol concentration when the gas to be measured can be simulated using alcohol, and for a PM2.5 sensor, the gas concentration is the dust concentration when the gas to be measured can be simulated using dust.

When the gas sensor is tested and calibrated, the controller 20 controls the concentration adjustment device 10 to work to change the gas concentration in the environment to form different gas concentration environments, for example, the gas concentration in the environment is changed through a plurality of increasing and/or decreasing operations, and at each gas concentration, the controller 20 obtains the detection value measured by the gas sensor, so as to obtain the detection value measured by the gas sensor at each gas concentration in the plurality of gas concentrations. The trend of the gas concentration can be determined according to actual test requirements, and for example, the trend can be increased all the time, decreased first and then increased, or the trend can be alternately increased and decreased.

Step 420: and comparing the detection value under each gas concentration with the standard value under the gas concentration to judge whether the gas sensor reaches the preset standard.

The standard value is a value to be regarded as an accurate value of the gas concentration as a judgment reference, and may be a value specified in advance or a detection result of a standard instrument. The detected value of the gas sensor can be compared with a standard value to determine whether the gas sensor meets the preset standard, for example, the controller 20 can calculate the difference between the detected value at each gas concentration and the standard value at the gas concentration, and determine whether the gas sensor meets the preset standard according to the difference. The controller 20 determines whether the gas sensor meets the predetermined standard by determining whether the detection accuracy of the gas sensor meets a predetermined requirement, the detection accuracy is obtained by comparing the detection value of the gas sensor with a standard value, for example, the difference between the detection value and the standard value can be used to represent the detection accuracy, and the controller 20 determines whether the gas sensor meets the predetermined standard, specifically, whether the difference between the detection value and the standard value is within a predetermined interval. The preset standard can be set according to actual needs.

When the controller 20 performs the judgment, the controller may perform the judgment once after controlling the concentration adjustment device 10 to adjust the gas concentration each time, and when the gas sensor is judged not to reach the preset standard, the controller does not perform the judgment for the next time by adjusting the gas concentration again, otherwise, the controller continues to adjust the gas concentration for the judgment until the preset times are reached; or the concentration adjusting device 10 may be controlled to adjust for a preset number of times, the comparison result between the detection value of the gas sensor and the standard value at each gas concentration is stored, and finally whether the gas sensor reaches the preset standard or not is judged according to all the comparison results. If the controller 20 determines that the gas sensor does not meet the predetermined criteria, step 430 is performed.

Step 430: the gas sensor is calibrated.

Specifically, the controller 20 may adjust the detection value of the gas sensor at a certain gas concentration to a standard value at the gas concentration, or to an average value of the detection values of a plurality of gas sensors of the same batch at the gas concentration; the gas sensor can also be calibrated in a compensation mode, and a compensation value is written into the gas sensor, so that the gas sensor can output the detection value after adding or subtracting the compensation value during each detection.

Step 440: a calibrated detection value of the calibrated gas sensor at each of the plurality of gas concentrations is obtained.

Specifically, after calibration, the controller 20 controls the concentration adjustment device 10 to operate to change the gas concentration in the environment, and obtains the calibration detection value measured by the calibrated gas sensor at each of the plurality of gas concentrations, and reference may be made to step 410 for a specific process of obtaining the calibration detection value measured by the calibrated gas sensor at each of the plurality of gas concentrations, which is not described herein again.

Step 450: and comparing the calibration detection value under each gas concentration with the standard value under the gas concentration to judge whether the calibrated gas sensor reaches the preset standard or not.

For the specific process of the determination, refer to step 420, and will not be described herein.

In the embodiment, because the gas sensor is tested under a plurality of gas concentrations, the detection value measured under each gas concentration is compared with the standard value under the gas concentration to judge whether the gas sensor reaches the preset standard, compared with the single test, the accuracy is higher, and the false detection rate is reduced; the gas sensor which does not reach the preset standard is not directly eliminated, but is calibrated, and then the gas sensor is tested again to judge whether the calibrated gas sensor reaches the preset standard, so that the detection precision of the gas sensor is improved, the standard reaching rate is improved, and the loss of products which do not reach the standard and are caused by misdetection is effectively reduced.

In one embodiment, the gas sensor that meets the predetermined standard may be a good product, and the gas sensor that does not meet the predetermined standard may be further divided into an undetermined product and a defective product, wherein the defective product has a larger difference from the undetermined product to the predetermined standard. In step 420, the step of determining whether the gas sensor meets the preset standard includes determining whether the gas sensor is a good product, a defective product, or an undetermined product, and further, if the controller 20 determines that the gas sensor does not meet the preset standard, calibrating the gas sensor specifically includes: and if the gas sensor is judged to be the undetermined product, calibrating the gas sensor. The products to be determined can be considered to have calibration conditions and still reach the preset standard through calibration, and the defective products can be considered to have overlarge difference with the preset standard and cannot be corrected through calibration, so that the products are not calibrated any more.

On the basis of the above embodiment, as shown in fig. 5, steps 410 to 420 may include the following steps:

step 510: a first detection value measured by the gas sensor at a first gas concentration is acquired.

Specifically, the controller 20 controls the concentration adjustment device 10 to operate for a first preset time, so that the gas concentration in the environment is a first gas concentration, and a first detection value measured by the gas sensor at the first gas concentration is obtained.

Step 520: determining whether the difference between the first detection value and the first criterion value is within a first predetermined interval, if so, performing step 530, otherwise, performing step 540.

Wherein the first standard value is a standard value at the first gas concentration. The difference between the first detection value and the first standard value may be the first detection value minus the first standard value, or may be the first standard value minus the first detection value. The controller 20 determines whether the gas sensor meets the predetermined standard according to whether the difference is within a predetermined interval. The first preset interval can be set according to the gas type and the gas concentration, for example, for the TVOC sensor, the first preset interval can be set to [ -10,10] or an interval smaller than [ -10,10], and when the gas concentration is smaller, the difference between the first detection value and the first standard value should be smaller, so the interval can be set smaller than [ -10,10 ].

Step 530: and judging that the gas sensor is good.

Step 540: and acquiring a second detection value measured by the gas sensor at a second gas concentration.

Specifically, the controller 20 controls the concentration adjustment device 10 to operate for a second preset time, so that the gas concentration in the environment is a second gas concentration, and a second detection value measured by the gas sensor at the second gas concentration is obtained.

The change in the gas concentration may be a decrease and then increase or increase (i.e., the first gas concentration is less than the second gas concentration), or may be an increase and then decrease or decrease (i.e., the first gas concentration is greater than the second gas concentration), which is not limited herein.

Step 550: and judging whether the difference value between the second detection value and the second standard value is within a second preset interval, if so, executing step 560, and otherwise, executing step 570.

Wherein the second standard value is a standard value at a second gas concentration. Step 520 may be referred to in this step, and is not described herein again.

Step 560: and judging that the gas sensor is an undetermined product.

Step 570: and judging the gas sensor to be a defective product.

On the basis of the above embodiment, the calibration of the gas sensor in step 430 may specifically be to obtain a compensation value according to a difference between the second detection value and the second standard value, and write the compensation value into the gas sensor.

In one embodiment, as shown in FIG. 6, steps 440-450 may include the steps of:

step 610: and acquiring a third detection value measured by the calibrated gas sensor at a third gas concentration.

Specifically, the controller 20 controls the concentration adjustment device 10 to operate for a third preset time, so that the gas concentration in the environment is a third gas concentration, and a third detection value measured by the calibrated gas sensor at the third gas concentration is obtained.

Step 620: and judging whether the difference value between the third detection value and the third standard value is within a third preset interval, if not, executing the step 630, and if so, executing the step 640.

Wherein the third standard value is a standard value at a third gas concentration. The difference between the third detection value and the third criterion value may be the third detection value minus the third criterion value, or may be the third criterion value minus the third detection value. The controller 20 determines whether the calibrated gas sensor meets the preset standard according to whether the difference is within a third preset interval. It can be understood that the difference between the third detection value and the third standard value should be smaller than the difference between the detection value and the standard value before calibration, and therefore the third predetermined interval should be smaller than the second predetermined interval to ensure the validity of calibration. The third predetermined interval may be set according to the gas type and the gas concentration, for example, for the TVOC sensor, if the second predetermined interval is [ -10,10], the third predetermined interval may be [ -5,5] or a smaller interval than [ -5,5 ].

Step 630: and judging that the gas sensor does not meet the preset standard. Specifically, the gas sensor may be determined to be defective.

Step 640: and acquiring a fourth detection value measured by the gas sensor at a fourth gas concentration.

Specifically, the controller 20 controls the concentration adjustment device 10 to operate for a fourth preset time, so that the gas concentration in the environment is a fourth gas concentration, and a fourth detection value measured by the gas sensor at the fourth gas concentration is obtained.

Likewise, the change of the gas concentration may be decreased first and then increased or increased all the time (i.e., the third gas concentration is less than the fourth gas concentration), or may be increased first and then decreased or decreased all the time (i.e., the third gas concentration is greater than the fourth gas concentration), which is not limited herein.

Step 650: and judging whether the difference value between the fourth detection value and the fourth standard value is within a fourth preset interval, if so, executing step 660, and otherwise, executing step 670.

Wherein the fourth standard value is a standard value at a fourth gas concentration. Step 620 may be referred to in this step, and will not be described herein.

Step 660: and judging that the gas sensor reaches a preset standard. Specifically, the gas sensor may be determined to be good.

Step 670: and judging that the gas sensor does not meet the preset standard. Specifically, it may be determined that the gas sensor is a defective product.

On the basis of the above embodiment, the second gas concentration may be greater than the first gas concentration, the third gas concentration may be greater than the second gas concentration, and the fourth gas concentration may be smaller than the third gas concentration, so that the gas concentrations generally have a tendency to increase and then decrease.

In order to provide a clearer understanding of the system and method for testing and calibrating a gas sensor provided by the present application, a PCBA equipped with a TVOC sensor is taken as an example and is illustrated below.

TVOC is an organic substance with saturated vapor pressure over 133.32Pa at room temperature, the boiling point of the TVOC is 50-250 ℃, the TVOC can exist in air in a form of evaporation at room temperature, and the TVOC has toxicity, irritation, carcinogenicity and special smell and can cause acute damage to human bodies. The TVOC sensor is a device or a device for detecting the TVOC concentration in the air by adopting a semiconductor gas sensitive element, and can convert related information into an electric signal so as to detect, analyze and alarm gas to be detected. It has high sensitivity detection reaction to the gaseous compounds of benzene, alkane, arene, olefin, halohydrocarbon, ester, aldehyde, ketone, etc.

The theory of operation of TVOC sensor is fairly simple, and when having TVOC gas in the air, the conductivity of TVOC sensor can change, and the concentration of this gas is higher, and the conductivity of TVOC sensor is just higher, and the signal of telecommunication through appropriate amplifier circuit collection TVOC sensor can turn into gas concentration detection value. However, different TVOC sensors of the same type often have differences in detection accuracy due to manufacturing process reasons or other environmental reasons such as high temperature, high humidity, etc.

The TVOC sensor can be used for manufacturing products such as air health partners, and the main function of the products is to detect whether the TVOC concentration in the air of the environment exceeds the standard or not. TVOC air quality detection products generally comprise a PCBA containing a TVOC sensor and a digital display screen. Because the supplied materials quality of TVOC sensor differs, the defective products that the supplied materials exist need carry out the effective test at the production end and detect, can carry out parameter calibration to some TVOC sensors that accord with the condition simultaneously and promote the detection precision. Therefore the product need guarantee the detection accurate nature of TVOC sensor before shipment, and need carry out a large amount of PCBA subsides in process of production and paste the dress, how to detect the detection precision of the TVOC sensor on the PCBA who produces high-efficiently whether reaches the standard of leaving the factory to and how to carry out effectual calibration to the TVOC sensor that detects the precision and does not reach standard, be the huge problem that faces in the production test always.

There are several methods for testing TVOC sensors in the prior art, but these methods still have some disadvantages.

In some prior arts, a TVOC concentration detection is realized by using a secondary pyrolysis gas-suction chromatography or a capillary gas mass spectrometry, but both methods need to use a gas chromatograph and a large number of sampling tubes to finish a high-precision TVOC gas concentration test, and the TVOC gas concentration test cannot be used in a production field due to factors such as high price of test equipment, long test time, complex operation of the test equipment, high toxicity and harmful risks of the gas to be tested, and the like, and is only suitable for laboratories or scientific research detection mechanisms.

In the prior art, only the sensor with the overlarge detection precision error in the tested TVOC sensor can be screened out and eliminated as a defective product, and after the TVOC sensor is welded on the PCBA through a surface mounting or plug-in process, no method is provided for effectively testing and calibrating the TVOC sensor on the PCBA.

As the alcohol of simulation TVOC gas, the alcohol concentration detection is carried out by being detected the TVOC sensor after often volatilizing it in prior art, not only need consume the plenty of time and wait for the alcohol to volatilize, and the alcohol that different batches of TVOC sensors will detect volatilizes the concentration and receives test environment temperature's influence very big moreover, leads to making the alcohol concentration detected value have very big difference because of the temperature difference when summer and winter to lead to the misdetection.

The application provides a test and calibration system and method of TVOC sensor, mainly is applied to the production field test scene, and the technical problem of main solution is how to carry out the high efficiency test to the PCBA who is equipped with the TVOC sensor and intercept the outflow of defective products to and how to carry out effectual calibration to the TVOC sensor.

In one embodiment, please refer to fig. 7 and 8, a testing and calibrating system for a TVOC sensor is provided. The system includes a housing 87 such that the entire system forms a TVOC gas tight box. The concentration adjusting device of the system comprises a magnetic ion fan 81, an air purifier 82 and a piezoelectric ultrasonic atomizer 83 (hereinafter referred to as an "ultrasonic atomizer 83"), wherein the magnetic ion fan 81 and the air purifier 82 are concentration reducing devices, the ultrasonic atomizer 83 is a concentration increasing device, and the alcohol concentration in the TVOC gas sealed box can be increased or reduced by controlling the opening and closing time lengths of the magnetic ion fan 81, the air purifier 82 and the ultrasonic atomizer 83. The system acquires the standard value using an air quality detector 84 (only a display panel of the air quality detector 84 is shown in fig. 7) as a standard instrument. The controller of the system consists of an upper computer 85 and a lower computer 86, wherein the upper computer 85 is a test computer in a production test scene, the upper computer 85 is provided with test software for a user to operate and check a test result, and the lower computer 86 is an MCU control board. The magnetic ion fan 81, the air cleaner 82, the ultrasonic atomizer 83 as concentration increasing means, the air quality detector 84, and the lower computer 86 are located in a casing 87.

Referring to fig. 8, the lower computer 86 performs UART communication with the magnetic ion fan 81, the air purifier 82, the ultrasonic atomizer 83, and the air quality detector 84, performs I2C communication with a UUT (Unit Under Test, here, a PCBA equipped with a TVOC sensor to be tested), and the upper computer 85 performs USB communication with the lower computer 86, so that the upper computer 85 can control the magnetic ion fan 81, the air purifier 82, and the ultrasonic atomizer 83 to work through the lower computer 86, and acquire and display TVOC concentration detection data of the air quality detector 84 and the UUT.

In this embodiment, referring to fig. 9, the testing and calibrating system of the TVOC sensor further includes a power module 88, where the power module 88 supplies power to each device or equipment in the system, where AC220V power is supplied to the upper computer 85, the air purifier 82, and the ultrasonic atomizer 83, DC5V power is supplied to the UUT, DC24V power is supplied to the magnetic ion fan 81 and the air quality detector 84, and DC12V power is supplied to the lower computer 86.

On the basis of the testing and calibrating system of the TVOC sensor, in one embodiment, a testing and calibrating method of the TVOC sensor is provided, which is applied to the upper computer 85, please refer to fig. 10, and the method includes the following steps:

step 101: the upper computer 85 controls the ultrasonic atomizer 83 to close and prompts a user to open the door of the TVOC gas seal box.

Step 102: the upper computer 85 controls the magnetic ion fan 81 to be opened for ventilation, and controls the magnetic ion fan 81 to be closed after 1min and prompts a user to close the door of the TVOC gas seal box.

Step 103: the upper computer 85 controls the air purifier 82 to be opened for air purification, and controls the air purifier 82 to be closed after 2 min. At this time, the alcohol in the TVOC gas-tight box is basically exhausted, and the alcohol concentration is very low.

Step 104: the upper computer 85 acquires an alcohol concentration detection value Y1 of the air quality detector 84 and an alcohol concentration detection value X1 of the UUT, and calculates a difference M1 between the alcohol concentration detection values Y1 and X1.

Step 105: the upper computer 85 judges whether the absolute value | M1| of the difference value M1 is not more than 5, if so, executes step 106, and otherwise, executes step 107.

At this time, the sealed box is almost free of alcohol, so the alcohol concentration detection values of the air quality detector 84 and the UUT are close to 0, the error is small, the allowable range of the difference is [ -5,5], and if the difference is in the range, the UUT reaches the factory standard and is a good product.

Step 106: the upper computer 85 judges that the UUT is good and displays a green PASS character.

Step 107: the upper computer 85 controls the ultrasonic atomizer 83 to be opened for atomization to increase the alcohol concentration, and controls the ultrasonic atomizer 83 to be closed after 10 seconds.

Step 108: the upper computer 85 obtains an alcohol concentration detection value Y2 of the air quality detector 84 and an alcohol concentration detection value X2 of the UUT, and calculates a difference M2 between the alcohol concentration detection values Y2 and X2.

Step 109: the upper computer 85 judges whether the absolute value | M2| of the difference M2 is not greater than 10, if so, performs step 111, and otherwise performs step 110.

At this time, the alcohol concentration in the seal box is increased, the allowed error is small, so the allowed interval of the difference is large, namely [ -10,10], if the difference is still not in the allowed interval, the UUT is possibly damaged, the calibration condition is not provided, and the UUT is a defective product.

Step 110: the upper computer 85 judges that the UUT is a defective product and displays a red FAIL character.

Step 111: the upper computer 85 displays an orange TBD character, calculates a compensation value C2, and writes the compensation value C2 into the MCU on the PCBA in the UUT.

The term "TBD" is an english abbreviation of "To be determined" and indicates a To-be-determined item, and here, the UUT is not good but has a calibration condition, and is not calibrated for a while, and after being calibrated, whether the UUT is good or not is determined. If X2 is less than Y2, the compensation value C2= | X2-Y2|, and if X2 is greater than Y2, the compensation value C2= - | X2-Y2|, the upper computer 85 writes the compensation value C2 into the MCU on the PCBA in the UUT, so that the MCU on the PCBA outputs the detection value after adding the compensation value C2 to the detection value every time of detection, thereby realizing calibration.

Step 112: the upper computer 85 controls the ultrasonic atomizer 83 to be opened for atomization so as to increase the alcohol concentration, and controls the ultrasonic atomizer 83 to be closed after 10 seconds.

And step 113: the upper computer 85 acquires an alcohol concentration detection value Y3 of the air quality detector 84 and an alcohol concentration detection value X3 of the UUT, and calculates a difference M3 between the alcohol concentration detection values Y3 and X3.

Step 114: the upper computer 85 judges whether the absolute value | M3| of the difference M3 is not greater than 5, if so, performs step 115, and otherwise performs step 110.

And (4) the allowable error after calibration is smaller, so that the allowable interval of the difference is smaller and is [ -5,5], and if the difference is not in the interval, the UUT still does not reach the factory standard and is a defective product.

Step 115: the upper computer 85 controls the air purifier 82 to be opened for air purification, and controls the air purifier 82 to be closed after 2 min.

Step 116: the upper computer 85 acquires an alcohol concentration detection value Y4 of the air quality detector 84 and an alcohol concentration detection value X4 of the UUT, and calculates a difference M4 between the alcohol concentration detection values Y4 and X4.

Step 117: the upper computer 85 judges whether the absolute value | M4| of the difference value M4 is not more than 5, if so, executes step 106, and otherwise, executes step 110.

And at the moment, judging again after adjusting the alcohol concentration, if the difference is not in the allowable interval, determining that the product is defective, otherwise, determining that the product is non-defective.

In one embodiment, an alcohol lamp or the like may be used to heat alcohol to increase the alcohol concentration instead of the ultrasonic atomizer 83. In one embodiment, the alcohol concentration may also be reduced by opening the doors of the TVOC gas-tight box for ventilation, instead of the air cleaner 82.

It should be noted that, the testing and calibrating system and method for a TVOC sensor in the above embodiments may not only test and calibrate one UUT, but also simultaneously place multiple UUTs in the system for testing and calibrating, so as to improve efficiency. The number of calibrations is not limited and multiple calibrations may be performed, for example, after step 117, a calibration similar to step 111 may be performed again, after which the UUT is tested again with increasing or decreasing alcohol concentration. The system and the method can be used for testing and calibrating not only the PCBA equipped with the TVOC sensor, but also equipment such as an air quality detector equipped with the TVOC sensor.

The testing and calibration system and method of the TVOC sensor of the above embodiment have the following advantages over the prior art:

first, a real-time feedback mechanism is employed to enable testing and calibration of a PCBA equipped with TVOC sensors. Wherein, the control board with MCU is used as a lower computer and the PCBA with the TVOC sensor is used for I ² C, communication is carried out, so that a TVOC concentration detection value reported by the TVOC sensor in real time is obtained; the control panel that takes MCU is used as the next machine and air quality detector to carry out the UART communication equally, acquires the TVOC concentration detection value of air quality detector in real time, and the host computer makes a difference with two TVOC concentration detection values to judge whether the difference is in presetting the interval (being reasonable error range) within, whether this judgement is equipped with the PCBA of TVOC sensor and reaches the standard of leaving the factory. And for the PCBA which does not reach the factory standard temporarily, writing the compensation value into the MCU on the PCBA to realize calibration. Testing and calibration of a PCBA equipped with a TVOC sensor is thus enabled.

Secondly, use this system can realize automatic batch test and be equipped with the PCBA of TVOC sensor, does not need the user to carry out manual operation and test, has promoted the on-the-spot efficiency of software testing effectively.

Thirdly, the user can operate and check the test result through the upper computer, the precision of the TVOC sensor is not required to be tested after the PCBA is assembled into a finished product complete machine with a display screen, the problem that the machine needs to be disassembled and reworked if defective products exist is solved, and the production and test efficiency is greatly improved.

Fourthly, the system and the method can compensate the detection precision of the TVOC sensor on the PCBA to realize calibration, thereby improving the detection precision and consistency of products and effectively reducing the loss of defective products caused by misdetection.

Fifthly, the piezoelectric ultrasonic atomizer is used for atomizing alcohol in the alcohol storage tank to increase the alcohol concentration in the air, the air purifier and the magnetic ion fan are used for reducing the alcohol concentration in the air, the time for increasing the alcohol concentration is shortened, the alcohol concentration in the air can be controlled by controlling the piezoelectric ultrasonic atomizer, the air purifier and the magnetic ion fan to be opened for a long time, the operation is convenient, and the consistency of the test environment of each batch of TVOC sensors can be ensured.

And sixthly, the air quality detector is used as a standard instrument, the TVOC detection precision of the air quality detector can reach the standard of a PID photoion analysis detection instrument, and the positive and negative deviation does not exceed 2%, so that the detection result is very accurate, the price is relatively low, the air quality detector is suitable for a production test field, regular metering and calibration are supported, and the accuracy of a standard value can be ensured. The testing process of TVOC sensors in different batches can use the detection result of the air quality detector as a standard value, and the consistency of the detection precision of the TVOC sensors can be improved.

Seventh, the alcohol concentration is increased and then decreased in the testing process, so that the alcohol consumption and the testing time can be saved.

Eighth, all test data are recorded and stored through upper computer test software, and the production data of the product can be traced in the later period conveniently.

It should be understood that although the various steps in the flowcharts of fig. 4-6, 10 are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least some of the steps in fig. 4-6 and 10 may include multiple sub-steps or multiple stages that are not necessarily performed at the same time, but may be performed at different times, and the order of performing the sub-steps or stages is not necessarily sequential, but may be performed alternately or alternatingly with other steps or at least some of the sub-steps or stages of other steps.

In one embodiment, an electronic device is further provided, which includes a memory and a processor, where the memory stores a computer program, and the processor implements the steps of the above method embodiments when executing the computer program.

In an embodiment, a computer-readable storage medium is provided, in which a computer program is stored which, when being executed by a processor, carries out the steps of the above-mentioned method embodiments.

It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in the embodiments provided herein may include non-volatile and/or volatile memory, among others. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically Programmable ROM (EPROM), electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double Data Rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous Link DRAM (SLDRAM), rambus (Rambus) direct RAM (RDRAM), direct Rambus Dynamic RAM (DRDRAM), and Rambus Dynamic RAM (RDRAM), among others.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A method of testing and calibrating a gas sensor, comprising:

2. The test and calibration method of claim 1, wherein comparing the detected value at each gas concentration with a standard value at that gas concentration to determine whether the gas sensor meets a predetermined standard comprises: and calculating the difference value between the detection value under each gas concentration and the standard value under the gas concentration, and judging whether the gas sensor reaches a preset standard or not according to the difference value.

3. The test and calibration method of claim 1, wherein said determining whether said gas sensor meets a predetermined criteria comprises: judging whether the gas sensor is a good product, a defective product or an undetermined product, wherein the good product is the gas sensor meeting the preset standard, and the defective product and the undetermined product are the gas sensors not meeting the preset standard;

if the gas sensor is judged not to reach the preset standard, calibrating the gas sensor as follows:

and if the gas sensor is judged to be the undetermined product, calibrating the gas sensor.

4. The test and calibration method of claim 3, wherein the obtaining a detected value of the gas sensor at each of a plurality of gas concentrations, and comparing the detected value at each gas concentration with a standard value at the gas concentration to determine whether the gas sensor meets a preset standard comprises:

acquiring a first detection value measured by the gas sensor under a first gas concentration;

judging whether the difference value between the first detection value and a first standard value is within a first preset interval, if so, judging that the gas sensor is good, and otherwise, acquiring a second detection value measured by the gas sensor under a second gas concentration;

and judging whether the difference value between the second detection value and a second standard value is within a second preset interval, if so, judging that the gas sensor is a to-be-determined product, and otherwise, judging that the gas sensor is a defective product.

5. The test and calibration method of claim 4, wherein calibrating the gas sensor comprises:

and obtaining a compensation value according to the difference value of the second detection value and a second standard value, and writing the compensation value into the gas sensor.

6. The test and calibration method according to any one of claims 2 to 5, wherein the obtaining of the calibration detection value of the calibrated gas sensor at each of the plurality of gas concentrations and the comparing of the calibration detection value at each gas concentration with the standard value at the gas concentration to determine whether the calibrated gas sensor meets the preset standard comprises:

acquiring a third detection value measured by the calibrated gas sensor under a third gas concentration;

judging whether the difference value between the third detection value and a third standard value is within a third preset interval, if not, judging that the gas sensor does not reach a preset standard, and if so, acquiring a fourth detection value measured by the gas sensor under a fourth gas concentration;

and judging whether the difference value of the fourth detection value and a fourth standard value is within a fourth preset interval, if so, judging that the gas sensor reaches a preset standard, and otherwise, judging that the gas sensor does not reach the preset standard.

7. A system for testing and calibrating a gas sensor, comprising:

8. The test and calibration system of claim 7 wherein comparing the sensed value for each gas concentration to a standard value for that gas concentration to determine whether the gas sensor meets a predetermined standard comprises: and calculating the difference value between the detection value under each gas concentration and the standard value under the gas concentration, and judging whether the gas sensor reaches a preset standard or not according to the difference value.

9. The test and calibration system of claim 7 wherein said determining whether said gas sensor meets a predetermined criteria comprises: judging whether the gas sensor is a good product, a defective product or an undetermined product, wherein the good product is the gas sensor meeting the preset standard, and the defective product and the undetermined product are the gas sensors not meeting the preset standard;

if the gas sensor is judged not to reach the preset standard, calibrating the gas sensor as follows: and if the gas sensor is judged to be the undetermined product, calibrating the gas sensor.

10. The test and calibration system of claim 9 wherein the controller controls the concentration adjustment device to operate to change the gas concentration in the environment, obtain a measurement of the gas sensor at each of a plurality of gas concentrations, and compare the measurement at each gas concentration with a standard value at that gas concentration to determine whether the gas sensor meets a predetermined standard, comprising:

controlling the concentration adjusting device to work for a first preset time so that the concentration of the gas in the environment is a first gas concentration;

acquiring a first detection value measured by the gas sensor under the first gas concentration;

judging whether the difference value of the first detection value and a first standard value is within a first preset interval, if so, judging that the gas sensor is good, otherwise, controlling the gas concentration changing device to work for a second preset time so that the gas concentration in the environment is a second gas concentration, and acquiring a second detection value measured by the gas sensor under the second gas concentration;

and judging whether the difference value between the second detection value and a second standard value is within a second preset interval, if so, judging that the gas sensor is an undetermined product, and otherwise, judging that the gas sensor is a defective product.

11. The test and calibration system of claim 10 wherein the controller calibrates the gas sensor, comprising:

12. The test and calibration system of any one of claims 8 to 11, wherein the controller controls the concentration adjustment device to operate to change the gas concentration in the environment, obtains a calibration detection value of the calibrated gas sensor at each of a plurality of gas concentrations, and compares the calibration detection value at each gas concentration with a standard value at the gas concentration to determine whether the calibrated gas sensor meets a preset standard, comprising:

controlling the concentration adjusting device to work for a third preset time so that the concentration of the gas in the environment is a third gas concentration;

acquiring a third detection value of the gas sensor after calibration, wherein the third detection value is measured under the third gas concentration;

judging whether the difference value between the third detection value and a third standard value is within a third preset interval, if not, judging that the gas sensor does not reach a preset standard, if so, controlling the concentration adjusting device to work for a fourth preset time so that the gas concentration in the environment is a fourth gas concentration, and acquiring a fourth detection value measured by the gas sensor under the fourth gas concentration;

13. The test and calibration system according to any one of claims 7 to 12, further comprising an air quality detector, wherein detection results of the air quality detector at different gas concentrations are taken as standard values at the corresponding gas concentrations.

14. An electronic device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor, when executing the computer program, implements the steps of the test and calibration method according to any of claims 1 to 6.

15. A computer-readable storage medium, characterized in that the medium has stored thereon a program which is executable by a processor to implement the test and calibration method according to any one of claims 1 to 6.