CN219608828U - Nitrogen detection device - Google Patents

Abstract

The utility model provides a nitrogen detection device, which comprises a base, a cover plate and an accessory circuit module, wherein the cover plate is covered on the base and forms an inner cavity; the base is provided with an air inlet, an air outlet and a lead interface; the air inlet and the air outlet are respectively arranged on two end surfaces of the base; the lead interface is arranged on the side surface of the base, the auxiliary circuit module is arranged in the inner cavity and is connected with external equipment through the lead interface, and the auxiliary circuit module comprises a nitrogen sensing module, a processor module, an air pressure detection module and a temperature and humidity detection module; the nitrogen sensing module adopts a semiconductor oxygen sensor, is connected with the processor module and is used for detecting the oxygen concentration in the environment and outputting data to the processor module, and the processor module reversely calculates the detected oxygen concentration as the nitrogen concentration; the air pressure detection module is connected with the processor module and is used for detecting the ambient air pressure and outputting the ambient air pressure to the processor module.

Description

Nitrogen detection device

Technical Field

The utility model belongs to the field of nitrogen detection, and particularly relates to a nitrogen detection device.

Background

The common nitrogen sensor is divided into a nitrogen mass spectrometer, an electrochemical nitrogen sensor and the like according to the detection principle. The nitrogen mass spectrometer can measure the nitrogen content by adopting a mass spectrometry; the electrochemical nitrogen sensor adopts the oxygen measuring principle, converts the oxygen concentration in the gas into an electric signal through the sensor, and calculates the nitrogen content through the calculation of a subtracter, and directly displays the percentage content of the nitrogen in the measured gas. There is no semiconductor sensor for detecting nitrogen, mainly because the semiconductor gas sensor can only react with oxygen and cannot directly react with nitrogen.

Most semiconductor gas sensors exhibit different gas-sensitive properties under different environmental conditions, i.e. the actual performance of the sensor is a combined representation of the own performance and the influence of the environmental conditions, mainly temperature, gas pressure, etc. However, most semiconductor gas sensors usually only consider temperature feedback to compensate the temperature of the sensor, and do not consider the influence of ambient air pressure on the sensor, such as a MEMS semiconductor gas sensor, a manufacturing method thereof, and a gas detection method of chinese patent 201410244751.8, so there is still a factor affecting the accuracy of the sensor.

Disclosure of Invention

The utility model aims at overcoming the defects of the prior art and provides a nitrogen detection device.

In order to achieve the above purpose, the technical scheme adopted by the utility model is as follows:

the utility model provides a nitrogen detection device, which comprises a base, a cover plate and an accessory circuit module, wherein the cover plate is covered on the base and forms an inner cavity; the base is provided with an air inlet, an air outlet and a lead interface; the air inlet and the air outlet are respectively arranged on two end surfaces of the base and used for communicating the outer side surface and the inner cavity of the base; the lead interface is arranged on the side surface of the base; the auxiliary circuit module is arranged in the inner cavity and connected with external equipment through a lead interface, and comprises a nitrogen sensing module, a processor module, an output module, an air pressure detection module and a temperature and humidity detection module; the nitrogen sensing module is connected with the processor module by adopting a semiconductor oxygen sensor and is used for detecting the oxygen concentration in the environment and outputting data to the processor module; the processor module reversely calculates the detected oxygen concentration as nitrogen concentration; the air pressure detection module is connected with the processor module and is used for detecting the current ambient air pressure and outputting the current ambient air pressure to the processor module; the temperature and humidity detection module is connected with the processor module and is used for detecting the temperature and humidity of the current environment and outputting the detected temperature and humidity to the processor module; the output module is provided with the lead interface and is connected with the processor module and used for outputting the nitrogen concentration, the current ambient air pressure and the current ambient temperature and humidity to external equipment.

Based on the above, the outer side of the semiconductor oxygen sensor is provided with a protective cover for eliminating the impact of external airflow on the semiconductor oxygen sensor, and the protective cover is arranged on the circuit substrate of the auxiliary circuit module in an adhesive or welding mode; the protective cover is provided with vent holes for gas diffusion and circulation.

Based on the above, the semiconductor oxygen sensor comprises a pipe cap, a sensitive element and a pipe seat; the tube cap is connected with the tube seat through interference fit, and the sensitive element is encapsulated in an inner cavity formed by the tube cap and the tube seat; the tube seat comprises a base and a contact pin inserted on the base, the contact pin extends out of two ends of the base, one end of the contact pin is used as an output pin, and the other end of the contact pin is connected with a lead wire of the sensitive element;

the sensitive element comprises a gas sensitive material layer, a measuring electrode layer, a lead, a substrate, a heating electrode layer, a heating resistor layer and an insulating layer;

the upper end face of the substrate is sequentially provided with the measuring electrode layer and the gas-sensitive material layer, and the gas-sensitive material layer covers the measuring electrode layer;

the heating electrode layer, the heating resistor layer and the insulating layer are sequentially arranged on the lower end face of the substrate, and the insulating layer covers the heating electrode layer and the heating resistor layer;

and the measuring electrode layer and the heating electrode layer respectively lead out two leads.

Compared with the prior art, the utility model has substantial characteristics and progress, and concretely comprises the following steps:

1. the nitrogen content is calculated out by the nitrogen detection device in a mode of measuring the oxygen content by the semiconductor principle, the principle is simple, the data is accurate, and the implementation is easy;

2. according to the utility model, the impact of ambient air flow on the sensor can be eliminated by arranging the protective cover outside the sensor, so that the stability of the sensor is improved;

3. according to the utility model, the nitrogen content is detected, and the air pressure, the temperature and the humidity in the environment are detected; when the nitrogen concentration is output, the corresponding ambient air pressure and ambient temperature and humidity are output, so that the external equipment can correct the nitrogen concentration when the nitrogen concentration is used, and the more accurate nitrogen concentration is obtained for self use.

Drawings

FIG. 1 is an external view of a nitrogen gas detecting apparatus according to the present utility model.

FIG. 2 is a schematic diagram of the principle structure of the nitrogen gas detecting device of the present utility model.

FIG. 3 is a schematic view showing the structure of a protective cover of the nitrogen gas detecting apparatus of the present utility model.

FIG. 4 is a schematic circuit diagram of a nitrogen gas detecting apparatus in example 2 of the present utility model.

Fig. 5 is a schematic diagram showing the structure of a semiconductor oxygen sensor in embodiment 3 of the present utility model.

Fig. 6 is a schematic structural diagram of a sensor in embodiment 3 of the present utility model.

Detailed Description

The technical scheme of the utility model is further described in detail through the following specific embodiments.

Example 1

As shown in fig. 1-2, a nitrogen gas detection device comprises a base 1, a cover plate 2 and an accessory circuit module 3, wherein the cover plate 2 is arranged on the base 1 in a covering manner and forms an inner cavity 4;

an air inlet hole 11, an air outlet hole 12 and a lead interface 13 are formed in the base 1; the air inlet hole 11 and the air outlet hole 12 are respectively arranged at two end surfaces of the base 1 and are used for communicating the outer side surface and the inner cavity of the base 1; the lead interface 13 is arranged on the side surface of the base 1; the auxiliary circuit module 3 is arranged in the inner cavity 4 and is connected with external equipment through a lead interface 13, and comprises a nitrogen sensing module 31, a processor module 32, an output module, a gas pressure detection module 33 and a temperature and humidity detection module 34;

the nitrogen sensing module 31 is connected with the processor module 32 by adopting a semiconductor oxygen sensor 311, and is used for detecting the oxygen concentration in the environment and outputting data to the processor module 32, and the processor module 32 reversely calculates the detected oxygen concentration as the nitrogen concentration;

the air pressure detection module 33 is connected with the processor module 32, and is used for detecting the current ambient air pressure and outputting the detected ambient air pressure to the processor module 32; the temperature and humidity detection module 33 is connected with the processor module 32, and is used for detecting the current environmental temperature and humidity and outputting the detected environmental temperature and humidity to the processor module 32;

the output module is provided with the lead interface 13 and is connected with the processor module, and is used for outputting the nitrogen concentration, the current ambient air pressure and the current ambient temperature and humidity to external equipment.

As shown in fig. 3, in order to eliminate the impact of external air flow on the sensor, the sensor is prevented from false alarm; the outer side of the semiconductor oxygen sensor 311 is provided with a protective cover 312 which is arranged on the circuit substrate of the auxiliary circuit module 3 in an adhesive or welding mode; the protective cover 312 is provided with a vent 313 for diffusing and circulating gas. The protective cover 312 may be made of stainless steel, copper, or plastic.

In this embodiment, the principle of back-calculating the detected oxygen concentration as the nitrogen concentration by the processor module is as follows: because the oxygen concentration in the environment has positive correlation with the oxygen adsorption concentration on the surface of the sensor sensitive material, namely, the higher the oxygen concentration in the environment is, the higher the oxygen adsorption concentration on the surface of the sensor sensitive material is, and the concentration of the adsorbed oxygen is not increased along with the increase of the oxygen concentration in the environment any more until the oxygen adsorption concentration on the surface of the material reaches saturation. The gas components in the air environment are mainly oxygen and nitrogen, other gases are relatively negligible, the oxygen concentration in the gas is converted into corresponding electric signal values through the sensor, and the corresponding electric signal values are processed by the processor, so that the nitrogen content can be calculated out. That is, assuming that the volume fraction of oxygen in the environment is a, the output value of an electric signal of the sensor in the environment is V, and when the sensor is placed in the environment with unknown concentration, if the output value of the electric signal of the sensor in the environment is V, the volume fraction of oxygen in the environment can be determined to be a, and then the volume fraction of nitrogen in the environment can be calculated to be 100-a.

The nitrogen gas detection device in this embodiment can output nitrogen gas concentration, current ambient air pressure, current ambient humiture to outer end equipment, not only considers the influence of humiture feedback to nitrogen gas concentration detection, has still considered the influence of ambient air pressure to nitrogen gas concentration detection simultaneously. After receiving the nitrogen concentration, the current ambient air pressure and the current ambient temperature and humidity, the external equipment can design a corresponding temperature and humidity and air pressure compensation algorithm by itself, so that the more accurate nitrogen concentration is obtained for self use.

Example 2

The present embodiment differs from embodiment 1 in that a specific nitrogen gas detection apparatus is provided.

In the nitrogen detection device of the embodiment, as shown in fig. 4, a processor module adopts an STM32F103 model chip, a pressure detection module adopts an LWP6130AV pressure sensor, and a temperature and humidity detection module adopts a WHT20 temperature and humidity sensor.

Example 3

The present embodiment differs from embodiment 1 in that a specific structure of the semiconductor oxygen sensor is provided.

As shown in fig. 5-6, the semiconductor oxygen sensor 311 includes a cap 3111, a sensing element 3112, and a tube socket 3113; the tube cap 3111 is connected with the tube seat 3113 through interference fit, and the sensitive element 3112 is encapsulated in an inner cavity formed by the tube cap 3111 and the tube seat 3113; the tube holder 3113 includes a base 31131 and a pin 31132 inserted on the base 31131, the pin 31132 extends out of two ends of the base 31131, one end is used as an output pin, and the other end is connected to a lead 31123 of the sensor 3112;

the sensing element includes a gas sensitive material layer 31121, a measuring electrode layer 31122, a lead 31123, a substrate 31124, a heating electrode layer 31125, a heating resistor layer 31126, and an insulating layer 31127;

the upper end surface of the substrate 31124 is provided with the measuring electrode layer 31122 and the gas-sensitive material layer 31121 in sequence, and the gas-sensitive material layer 31121 covers the measuring electrode layer 31122;

the lower end surface of the substrate 31124 is provided with the heating electrode layer 31125, the heating resistor layer 31126 and the insulating layer 31127 in this order, and the insulating layer 31127 covers the heating electrode layer 31125 and the heating resistor layer 31126;

the measuring electrode layer 31122 and the heating electrode layer 31125 draw out two leads, respectively.

Specifically, the substrate can be made of double-sided polished alumina ceramic, the heating electrode layer and the measuring electrode layer can be made of gold, silver or platinum, the heating resistor layer can be made of ruthenium oxide or platinum metal, the insulating layer is made of insulating ceramic or glass, silicon oxide or silicon nitride, and the gas-sensitive material layer is made of SnO ₂ 、WO ₃ 、In ₂ O ₃ 、Fe ₂ O ₃ ZnO, niO and Co ₃ O ₄ One or more metal oxide semiconductor materials of the following materials.

It should be noted that the heating electrode layer, the measuring electrode layer, the heating resistor layer, and the insulating layer may be fabricated on the substrate by conventional screen printing. Wherein, the size and shape of the heating electrode layer and the measuring electrode layer may be unlimited.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present utility model and not for limiting the same; while the utility model has been described in detail with reference to the preferred embodiments, those skilled in the art will appreciate that: modifications may be made to the specific embodiments of the present utility model or equivalents may be substituted for part of the technical features thereof; without departing from the spirit of the utility model, it is intended to cover the scope of the utility model as claimed.

Claims (3)

1. The utility model provides a nitrogen gas detection device, includes base, apron and accessory circuit module, its characterized in that:

the cover plate is covered on the base and forms an inner cavity;

the base is provided with an air inlet, an air outlet and a lead interface; the air inlet and the air outlet are respectively arranged on two end surfaces of the base and used for communicating the outer side surface and the inner cavity of the base; the lead interface is arranged on the side surface of the base;

the auxiliary circuit module is arranged in the inner cavity and connected with external equipment through a lead interface, and comprises a nitrogen sensing module, a processor module, an output module, an air pressure detection module and a temperature and humidity detection module;

the nitrogen sensing module is connected with the processor module by adopting a semiconductor oxygen sensor and is used for detecting the oxygen concentration in the environment and outputting data to the processor module;

the processor module reversely calculates the detected oxygen concentration as nitrogen concentration;

the air pressure detection module is connected with the processor module and is used for detecting the current ambient air pressure and outputting the current ambient air pressure to the processor module;

the temperature and humidity detection module is connected with the processor module and is used for detecting the temperature and humidity of the current environment and outputting the detected temperature and humidity to the processor module;

the output module is provided with the lead interface and is connected with the processor module and used for outputting the nitrogen concentration, the current ambient air pressure and the current ambient temperature and humidity to external equipment.

2. The nitrogen gas detection apparatus according to claim 1, wherein: the semiconductor oxygen sensor is provided with a protective cover for eliminating the impact of external airflow on the semiconductor oxygen sensor, and the protective cover is arranged on a circuit substrate of the auxiliary circuit module in an adhesive or welding mode; the protective cover is provided with vent holes for gas diffusion and circulation.

3. The nitrogen gas detection apparatus according to claim 1, wherein: the semiconductor oxygen sensor comprises a pipe cap, a sensitive element and a pipe seat; the tube cap is connected with the tube seat through interference fit, and the sensitive element is encapsulated in an inner cavity formed by the tube cap and the tube seat; the tube seat comprises a base and a contact pin inserted on the base, the contact pin extends out of two ends of the base, one end of the contact pin is used as an output pin, and the other end of the contact pin is connected with a lead wire of the sensitive element;

the sensitive element comprises a gas sensitive material layer, a measuring electrode layer, a lead, a substrate, a heating electrode layer, a heating resistor layer and an insulating layer;

the upper end face of the substrate is sequentially provided with the measuring electrode layer and the gas-sensitive material layer, and the gas-sensitive material layer covers the measuring electrode layer;

the heating electrode layer, the heating resistor layer and the insulating layer are sequentially arranged on the lower end face of the substrate, and the insulating layer covers the heating electrode layer and the heating resistor layer;

and the measuring electrode layer and the heating electrode layer respectively lead out two leads.