阅读说明：本技术 氧量变送器 (Oxygen content transmitter ) 是由 尹卫 贾铁军 向蓝翔 丛中斗 高会玲 黄继东 韩月奇 王维华 张谦 于 2019-09-12 设计创作，主要内容包括：本发明提供一种氧量变送器,该氧量变送器包括密封箱体；设置在密封箱体的内部的壳体；设置在壳体的内部并且用于感测氧浓度信号的氧化锆测氧传感器；设置在壳体的内部并且用于感测被测气体的温度的第一温度传感器；用于感测室温温度的第二温度传感器；以及设置在壳体内并且用于处理来自氧化锆测氧传感器、第一温度传感器和第二温度传感器的信号并产生控制信号的信号处理及控制系统。根据本发明的氧量变送器还包括机械校准装置,该机械校准装置用于对信号处理和控制系统进行校准。本发明的氧量变送器采用机械校准装置,无需打开箱体盖即可对氧量变送器进行校准,在显示窗部分只需采用符合相关防爆标准的普通防爆玻璃即可,大大降低了生产成本。(The invention provides an oxygen transmitter, which comprises a sealed box body; a housing disposed inside the sealed case; a zirconia oxygen sensor disposed inside the housing and for sensing an oxygen concentration signal; a first temperature sensor disposed inside the housing and sensing a temperature of the measured gas; a second temperature sensor for sensing a room temperature; and a signal processing and control system disposed within the housing and configured to process signals from the zirconia oxygen sensor, the first temperature sensor, and the second temperature sensor and generate control signals. The oxygen transmitter according to the present invention further comprises a mechanical calibration device for calibrating the signal processing and control system. The oxygen transmitter of the invention adopts a mechanical calibration device, can calibrate the oxygen transmitter without opening the box body cover, and only needs to adopt common explosion-proof glass meeting the relevant explosion-proof standard on the display window part, thereby greatly reducing the production cost.)

1. An oxygen sensor comprising:

Sealing the box body;

the shell is arranged inside the sealed box body;

The zirconia oxygen measuring sensor is arranged inside the shell and used for sensing an oxygen concentration signal;

A first temperature sensor disposed inside the housing for sensing a temperature of a gas to be measured;

A second temperature sensor for sensing a room temperature;

A signal processing and control system disposed within the housing for processing signals from the zirconia oxygen sensor, the first temperature sensor and the second temperature sensor and generating control signals,

The oxygen transmitter is characterized by further comprising a mechanical calibration device, wherein the mechanical calibration device is used for calibrating the signal processing and control system.

2. The oxygen transmitter of claim 1, wherein:

The signal processing and control system includes a calibration potentiometer disposed on and extending outwardly from a housing of the oxygen transmitter, and the mechanical calibration device is disposed on the sealed housing and is operatively engaged with the calibration potentiometer.

3. The oxygen transmitter of claim 2, wherein:

the mechanical calibration device comprises an operating part for performing rotary operation on the calibration potentiometer and a rotary fixing component for arranging the operating part in a through hole formed in the protective shell.

4. the oxygen transmitter of claim 3, wherein:

The rotating fixture assembly includes a first bushing fixedly disposed on the protective housing and a second bushing rotatably disposed within the first bushing, the operating member being fixedly disposed within the second bushing.

5. the oxygen transmitter of claim 4, wherein:

a first circumferential groove is provided on a circumference of the operating member that contacts the second bush, and a seal ring is provided in the first circumferential groove.

6. The oxygen transmitter of claim 4, wherein:

A second circumferential groove is formed at a position of the operating member adjacent to an inner end side of the second bush, and an open retainer ring that snaps the operating member and the second bush together is provided in the second circumferential groove.

7. the oxygen transmitter of claim 1, wherein: the signal processing and control system comprises:

A first signal input end of the pre-amplification circuit is connected to a signal output end of the zirconia oxygen measurement sensor, a first signal output end of the pre-amplification circuit outputs an amplified oxygen potential signal, a second signal input end of the pre-amplification circuit is connected to a first temperature sensor for measuring the temperature of the gas to be measured, and a third signal input end of the pre-amplification circuit is connected to a second temperature sensor for measuring the room temperature;

the input end of the A/D conversion module is connected to the output end of the pre-amplification circuit;

The input end of the central processing unit is connected to the output end of the A/D conversion module; and

And the display module is controlled by the central processing unit to carry out digital display on the oxygen potential signal.

8. The oxygen transducer of claim 7, wherein the sensor is a sensor,

The signal processing and control system further comprises a temperature control module for controlling the temperature of the zirconia oxygen sensor, and the temperature control module controls the temperature of the zirconia oxygen sensor based on the temperature signal of the first temperature sensor.

9. The oxygen transducer of claim 7, wherein the sensor is a sensor,

The signal processing and control system further comprises a data selection module, wherein the data selection module is arranged between the pre-amplification circuit and the A/D conversion module and used for enabling the analog signal of the pre-amplification circuit to be selectively input to the A/D conversion module.

10. The oxygen transducer of claim 7, wherein the sensor is a sensor,

the signal processing and control system further comprises a standard current signal module, wherein the input end of the standard current signal module is connected to the central processing unit and outputs a standard current signal.

11. The oxygen transducer of claim 10, wherein the sensor is a sensor,

the standard current signal module comprises an optical coupling isolator, a D/A converter and a V/I converter, wherein the optical coupling isolator is used for receiving an oxygen potential signal from the central processing unit, the D/A converter is used for converting the oxygen potential signal into an analog signal, and the V/I converter is used for outputting a standard current signal.

Technical Field

The invention relates to the technical field of oxygen measuring equipment, in particular to oxygen measuring equipment with a mechanical calibration device.

Background

The oxygen transducer of zirconia is a new oxygen measuring instrument developed in recent years. The sensitive probe can be directly inserted into the flue for detection, and has the characteristics of simple structure, higher precision, quick response to oxygen content change and the like, so the sensitive probe is widely used for measuring the oxygen content of flue gas in various boilers and kilns. In addition, the zirconia oxygen quantity transducer can be conveniently matched with the regulator to form a closed-loop oxygen quantity control system, and low-oxygen combustion control is realized, so that the purposes of saving energy, reducing environmental pollution and the like are achieved. Therefore, the application of the method in actual production is wider and wider.

The zirconia oxygen measurement technology utilizes the oxygen concentration cell principle to measure the oxygen content in the gas. Under the ideal state, when the zirconia element reaches the working temperature and the oxygen content on the surfaces of the inner electrode and the outer electrode is unequal, an oxygen concentration difference battery is formed, the electromotive force of the battery is generated, and the relationship between the electromotive force of the battery and the oxygen concentration on the surfaces of the electrodes conforms to the Nernst equation:

in the formula:

E-oxygen concentration cell electromotive force, V;

R-gas constant, 8.3145J. mol^-1·K^-1；

F-Faraday constant, 96485.309℃ mol^-1；

T-absolute temperature, K;

P₀-reference gas oxygen partial pressure,%;

P-partial pressure of oxygen of the gas to be measured,%.

Because the actual measurement is not performed under the ideal condition due to various factors, the equation (1) needs to be corrected, and a new equation is obtained after the correction:

P₀Oxygen content in air (20.6%), k and E₀The values can be obtained by calibration. By measuring the potential signal E of a zirconia cell_mAnd the oxygen content P value of the detected gas is calculated by the oxygen transmitter according to the formula (2).

The zirconium oxide oxygen quantity transducer adopts an integrated design to complete the acquisition, conversion, operation and output of analog signals. When the system is used on site by a user, the oxygen measurement working curve of a zirconia battery needs to be calibrated regularly through a transmitter, the calibration design of a zirconia oxygen quantity transducer in the current market is usually realized by adopting menu setting, submenu setting and calibration data setting steps need to be carried out, particularly, an explosion-proof zirconia oxygen quantity transducer applied to explosive gas dangerous places needs to redesign a display part of a circuit control system of a non-explosion-proof zirconia oxygen quantity transducer, and the display window part needs to adopt an explosion-proof touch screen to realize field operation.

In addition, when the similar products in the market are applied to an industrial field, due to the fact that a large number of field high-power devices are arranged, interference is serious, and a targeted anti-interference design is not adopted, operation faults caused by field interference easily occur on the industrial field, normal operation of user equipment is affected, and the problems of high maintenance cost, low production efficiency and the like are caused.

Therefore, there is a need in the art for a zirconia oxygen level transmitter that can be calibrated while ensuring safety.

disclosure of Invention

In order to address at least one of the above-mentioned technical problems, embodiments of the present invention provide an oxygen sensor having a mechanical calibration device.

according to one aspect of the present invention, there is provided an oxygen transmitter comprising a sealed housing; a housing disposed inside the sealed case; a zirconia oxygen sensor disposed inside the housing and for sensing an oxygen concentration signal; a first temperature sensor disposed inside the housing and sensing a temperature of the measured gas; a second temperature sensor for sensing a room temperature; and a signal processing and control system disposed within the housing and configured to process signals from the zirconia oxygen sensor, the first temperature sensor, and the second temperature sensor and generate control signals. The oxygen transmitter according to the present invention further comprises a mechanical calibration device for calibrating the signal processing and control system.

in accordance with a preferred embodiment of the oxygen transmitter of the present invention, the signal processing and control system includes a calibration potentiometer disposed on and extending outwardly from the housing of the oxygen transmitter, and a mechanical calibration device disposed on the sealed housing and operatively engaged with the calibration potentiometer.

in another preferred embodiment of the oxygen sensor according to the present invention, the mechanical calibration means comprises an operating member for rotationally operating the calibration potentiometer and a rotationally fixed assembly for disposing the operating member in a through hole formed in the protective housing.

in accordance with yet another preferred embodiment of the oxygen transmitter of the present invention, the rotating fixture assembly includes a first bushing fixedly disposed on the protective housing and a second bushing rotatably disposed within the first bushing, the operating member being fixedly disposed within the second bushing.

In a further preferred embodiment of the oxygen sensor according to the invention, a first circumferential groove is provided on the circumference of the actuating element which comes into contact with the second sleeve, in which first circumferential groove a sealing ring is provided.

In accordance with a further preferred embodiment of the oxygen transmitter according to the present invention, a second circumferential groove is formed in the operating member at a position adjacent to the inner end side of the second liner, and a split collar is provided in the second circumferential groove, the split collar snapping the operating member and the second liner together.

In another preferred embodiment of the oxygen sensor according to the present invention, the signal processing and control system comprises: a first signal input end of the pre-amplification circuit is connected to a signal output end of the zirconia oxygen measurement sensor, a first signal output end of the pre-amplification circuit outputs an amplified oxygen potential signal, a second signal input end of the pre-amplification circuit is connected to a first temperature sensor for measuring the temperature of the gas to be measured, and a third signal input end of the pre-amplification circuit is connected to a second temperature sensor for measuring the room temperature; the input end of the A/D conversion module is connected to the output end of the pre-amplification circuit; the input end of the central processing unit is connected to the output end of the A/D conversion module; and the display module is controlled by the central processing unit to carry out digital display on the oxygen potential signal.

In accordance with still another preferred embodiment of the oxygen sensor of the present invention, the signal processing and control system further includes a temperature control module for controlling a temperature of the zirconia oxygen sensor, the temperature control module controlling the temperature of the zirconia oxygen sensor based on the temperature signal of the first temperature sensor.

In a further preferred embodiment of the oxygen sensor according to the present invention, the signal processing and control system further comprises a data selection module, the data selection module is disposed between the pre-amplification circuit and the a/D conversion module, and is configured to selectively input the analog signal of the pre-amplification circuit to the a/D conversion module.

In accordance with another preferred embodiment of the oxygen sensor of the present invention, the signal processing and control system further comprises a standard current signal module, wherein an input terminal of the standard current signal module is connected to the central processing unit and outputs a standard current signal.

in another preferred embodiment of the oxygen sensor according to the present invention, the standard current signal module comprises an optical isolator for receiving the oxygen potential signal from the central processing unit, a D/a converter for converting the oxygen potential signal into an analog signal, and a V/I converter for outputting the standard current signal.

Compared with the prior art, the oxygen transmitter with the mechanical calibration device has at least one of the following beneficial effects:

(1) The oxygen transmitter of the invention adopts the mechanical calibration device, and the oxygen transmitter can be adjusted without opening the box body cover, so that the display window part only needs to adopt common explosion-proof glass meeting the relevant explosion-proof standard, thereby greatly reducing the production cost.

(2) because mechanical calibration device sets up on oxygen volume changer's sealed box, can operate mechanical calibration device in the outside of sealed box, consequently make the convenient high efficiency of online calibration process.

(3) When the non-explosion-proof zirconia oxygen transducer is subjected to explosion-proof design, an explosion-proof touch screen is not needed to change the design of the original oxygen transducer, and the requirement of the oxygen transducer on explosion-proof performance can be met.

Drawings

Other objects and advantages of the present invention will be more readily understood and appreciated by reference to the following description of the invention taken in conjunction with the accompanying drawings, which are a full and enabling description of the invention as a whole.

FIG. 1 is a schematic view of an oxygen sensor having a mechanical calibration apparatus according to the present invention.

FIG. 2 is a schematic diagram of a mechanical calibration arrangement for an oxygen sensor in accordance with the present invention.

FIG. 3 is a schematic view of a signal processing and control system for an oxygen sensor according to the present invention.

It is noted that the drawings are not necessarily to scale and are merely illustrative in nature and not intended to obscure the reader.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings of the embodiments of the present invention. It should be apparent that the described embodiment is one embodiment of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention without any inventive step, are within the scope of protection of the invention.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs.

Aiming at the problems of complicated design, high material cost and complicated field operation steps of a zirconia oxygen quantity transmitter in the prior art, in particular to an explosion-proof type transmitter, the invention provides the zirconia oxygen quantity transmitter which realizes the calibration of an input potential signal by utilizing a hardware operational amplification circuit in a circuit control part and adjusts the operational amplification circuit for calibration by arranging a mechanical potentiometer.

An embodiment of the present invention provides an oxygen transmitter 10, as shown in FIG. 1, which shows a schematic diagram of oxygen transmitter 10 according to the present invention. The oxygen transmitter 10 comprises a sealed box 12, a housing 14 disposed inside the sealed box 12, a zirconia oxygen sensor 16 disposed inside the housing 14 for sensing an oxygen concentration signal, a first temperature sensor 18 disposed inside the housing 14 for sensing the temperature of a gas to be detected, a second temperature sensor 20 for sensing a room temperature, and a signal processing and control system 40 disposed inside the housing 14, the signal processing and control system 40 being configured to process signals from the zirconia oxygen sensor 16, the first temperature sensor 18, and the second temperature sensor 20 and generate control signals, and further, the oxygen transmitter 10 further comprises a mechanical calibration device 60 for calibrating the signal processing and control system 40.

sealed housing 12 may serve as the outermost housing for oxygen transmitter 10, and may be used to enclose and seal various sensors and control systems within, to meet relevant dust and water requirements. A transparent display window may be provided on the cover sealing the easy-to-view side of the case 12 to facilitate viewing or manipulating the relevant display data inside. A housing 14 is provided within the sealed enclosure 12, the housing 14 being used to mount and secure various sensors and control systems, such as a zirconia oxygen sensor 16, a first temperature sensor 18, a second temperature sensor 20, and a signal processing and control system 40. Because process variations can occur in the process model of signal processing and control system 40 over time and due to changes in the environment of use, which can lead to variations in the processing results, calibration of signal processing and control system 40 is required, and mechanical calibration device 60 is included in oxygen transmitter 10 to calibrate signal processing and control system 40. Mechanical calibration device 60 can be disposed in a sidewall of sealed housing 12 of explosion-proof type oxygen transmitter 10, so that signal processing and control system 40 can be calibrated directly by operating mechanical calibration device 60 without opening a cover of mechanical calibration device 60 during operation of explosion-proof type oxygen transmitter 10, thereby ensuring operational safety of explosion-proof type oxygen transmitter 10.

In an embodiment of the oxygen sensor 10 of the present invention, the cover of the non-explosion type zirconia oxygen sensor 10 may be rectangular, the cover is a part of the sealed box 12, a transparent display window is disposed on the cover, the periphery of the buckling position of the cover and the body is buckled inwards, for the waterproof and dustproof requirement of IP65 level, a rubber strip is adhered to the periphery of the inward buckling position of the cover, for sealing the connecting gap between the cover and the body, a cover-opening bolt may be disposed at the middle position of the right side edge of the cover in the vertical direction, the cover-opening bolt corresponds to the threaded post on the body, when the bolt and the threaded post are tightened, the rubber strip in the cover is tightly pressed and sealed with the upper outer edge of the body, so as to ensure the IP65 level sealing. Here, at least one mounting part, for example, a sheet-shaped mounting part, may be provided on the left side of the case body, the sheet-shaped mounting part may be fixedly provided on the left side of the case body in a horizontal manner, a mounting hole may be formed on an end of the sheet-shaped mounting part away from the case body, and a stopper notch may be formed on a side of the sheet-shaped mounting part facing the case body. Simultaneously, set up corresponding erection column on the downside border of the corresponding one side of box lid, namely, can set up the erection column respectively on the bottom side of box lid and the prominent border of orientation box body at top, two erection columns insert respectively about in the mounting hole of two slice installation departments, and two erection columns homoenergetic are rotatory in the mounting hole, thereby make the box lid can use the erection column to rotate around the box body as the axis, so that realize opening and closing of box lid for the box body. Spacing breach is used for when the box lid is opened to a certain extent, for example open to when forming 130 degrees left and right angles with the opening plane of box body, prevent the further rotation of box lid, for example spacing breach restricts the motion of box lid through the butt at the protruding border with the vertical side of box lid, thereby unscrew the bolt of uncapping and open the box lid clockwise and make the box lid rotatory 130 degrees when controlling, the box lid can be blocked, expose the operating means of changer with convenient operation from this, and can prevent that the box lid from taking place the transition rotation. Aiming at the requirement that the use site needs water resistance and dust resistance, the inside and the outside of the oxygen transmitter 10 can be sealed by screwing the uncapping bolt during the operation of the instrument. In the case of non-explosion type oxygen transmitter 10, for the purpose of calibration for field operation, a display panel may be provided on housing 14 inside sealed housing 12, thereby performing field calibration and key operation.

the explosion-proof grade of the explosion-proof oxygen transmitter 10 is two grades of ExdIIC and ExdIIB, and the two grades have different requirements on parameters such as the maximum clearance corresponding to the minimum width of the explosion-proof joint surface of the sealed box body 12, the explosion experiment times, the screw pitch of the threaded joint surface of the sealed box body 12, the number of joggles and the like. According to different explosion-proof technical requirements of two explosion-proof levels on the sealed box body 12, the ExdIIB-level explosion-proof sealed box body 12 is determined to be designed into a cubic box type upper turnover cover, and an explosion-proof combination surface is a plane rectangle. Since the explosion-proof sealed box body 12 is required to have the IP65 grade protection performance specified by the national standard, a sealing rubber ring is required to be added at the joint surface. The main body and the box cover of the sealed box body 12 can be fastened by adopting hexagon socket head cap bolts, the thread pitch of the bolts accords with the GB9144 standard, and the tolerance fit can meet the requirement of 6g/6H of GB 9145. The thread depth should be greater than the full height of the corresponding specification fastener nut; the thread should meet the 6H class requirement and the allowable clearance of the hole under the bolt head is less than the H13 class clearance specified by ISO 286-2. The contact area of the bolt head and the connected piece is larger than or equal to the contact area of the bolt in the unthreaded hole.

According to the national standard requirements, the Exd IIC explosion-proof grade does not allow a plane joint surface to be adopted, and the explosion-proof joint surface is required to be a thread joint surface, so that the case cover needs to be designed into a thread-jointed round cover. The main body and the box cover of the sealed box body 10 are fastened by adopting hexagon socket head cap bolts, and the requirement of a fastener is the same as that of Exd IIB explosion-proof grade design. The explosion-proof joint surface between the box cover and the main body of the sealed box 10 is combined in a spigot form. The spigot joint surface refers to the matching part of the box cover and the main body of the sealed box body. Specific requirements for the seam allowance combination are as follows: the flame path length of the spigot joint surface is in accordance with the requirements of GB3836.2-2000 tables 1-4; the matching roughness of the spigot joint surface is not less than Ra6.3.

The signal processing and control system 40 of the oxygen transmitter 10 of the present invention includes a calibration potentiometer 42, as shown in fig. 2, the calibration potentiometer 42 being disposed on the housing 14 of the oxygen transmitter 10 and extending outwardly from the housing 14, and a mechanical calibration device 60 being disposed on a panel of the sealed housing 12 and operatively engaged with the calibration potentiometer 42. The signal processing and control system 40 can comprise two calibration potentiometers 42, one for calibrating the slope of the nernst equation and the other for calibrating the intercept of the nernst equation, i.e. for calibrating the air and the standard gas, respectively. Thus, two mechanical calibration devices 60 are provided to operate calibration potentiometer 42 via respective mechanical calibration devices 60 to correct for errors in oxygen transmitter 10. Mechanical calibration device 60 is disposed on sealed housing 12 of oxygen sensor 10, signal processing and control system 40 is disposed within sealed housing 12, and mechanical calibration device 60 is operatively connected to calibration potentiometer 42 for rotational operation of calibration potentiometer 42 without opening the housing cover of sealed housing 12.

as shown in fig. 2, the calibration potentiometer 42 is fixedly disposed on the housing 14 by a boss 422 on one side of the housing 14 and a nut 142 on the other side of the housing 14. That is, the portion of the calibration potentiometer 42 that is located within the housing 14 has a larger dimension, while the portion of the calibration potentiometer 42 that passes through the through hole in the housing 14 and engages the housing 14 has a relatively smaller dimension, thereby forming a boss 422 on the portion of the calibration potentiometer 42 that contacts the inner side wall of the housing 14. External threads may be machined on the portion of calibration potentiometer 42 that extends through the wall of housing 14 to secure calibration potentiometer 42 to housing 14 via nut 142, where housing 14 may be a faceplate for oxygen transmitter 10.

Mechanical calibration apparatus 60 of oxygen transmitter 10 of the present invention can include an operating member 602 and a rotating fixture assembly 604 for positioning operating member 602 within a bore formed in sealed housing 12. Operator element 602 can be directly engaged with calibration potentiometer 42 to operate calibration potentiometer 42, and pivoting fixture assembly 604 can be used to rotatably mount operator element 602 within sealed housing 12 of oxygen sensor 10.

The rotationally fixed assembly 604 may include a first bushing 6042 fixedly disposed on the sealed housing 12 and a second bushing 6044 rotatably disposed within the first bushing 6042, the operational component 602 being fixedly disposed within the second bushing 6044. Here, the first bushing 6042 may be fixedly disposed on the sealed housing 12 in a fixing manner commonly used in the art, such as by welding, bonding, interference fit, or the like.

In order to ensure the explosion-proof effect of oxygen sensor 10, that is, to ensure the sealing performance of mechanical calibration device 60, a first circumferential groove 6024 is provided on the circumference of operating member 602 in contact with second bushing 6044, a seal ring 6026 is provided in first circumferential groove 6024, and a good seal is achieved between the two by seal ring 6026 provided between the outer circumferential wall of operating member 602 and second bushing 6044, so that the main components of oxygen sensor 10 are sealed inside sealed housing 12.

further, in order to relatively fix the operation member 602 and the second bush 6044, a second circumferential groove 6028 is formed at a position of the operation member 602 adjacent to the inner end side of the second bush 6044, and a circlip 6030 is provided in the second circumferential groove 6028, the circlip 6030 snapping the operation member 602 and the second bush 6044 together. Thereby, it is possible to cause the operation member 602 to rotate together with the second bush 6044 within the first bush 6042 when the operation member 602 is rotated by an external force. Here, the second bushing 6044 may be made of a copper material, such as a copper bush, and the length of the explosion-proof joint face between the first bushing 6042 and the operation member 602 may be increased by the second bushing 6044, and thus the tightness of the joint face may be enhanced, and rusting of the members at the position of mutual contact may also be prevented by the copper bush.

in order to achieve the operable engagement of the operating member 602 with the calibration potentiometer 42, a connecting groove 424 is formed on an end portion of the calibration potentiometer 42 operatively connected with the operating member 602, and a protrusion 6032 engaged with the connecting groove 424 is formed on a corresponding end portion of the operating member 602, whereby the operable engagement of the operating member 602 with the calibration potentiometer 42 can be achieved by inserting the protrusion 6032 into the connecting groove 424 during mounting.

In order to facilitate the operation of the operating member 602, a slip-preventing structure, such as a plurality of densely arranged protrusions, or a plurality of ribs arranged in an inclined or parallel manner in the axial direction, or other structures capable of increasing friction, may be provided on the outer periphery of the operating portion of the operating member 602 exposed to the outside of the sealed case 12. In the embodiment shown in fig. 1, a driving groove 6034 is provided on the outer end side of the operation member 602, and the operation member 602 can be rotationally operated by a screwdriver through the driving groove 6034.

The signal processing and control system 40 of the oxygen sensor 10 of the present invention comprises a preamplifier circuit 43, an A/D conversion module 44, a central processing unit 46 and a display module 48, as shown in FIG. 3. A first signal input terminal of the pre-amplifier circuit 43 is connected to a signal output terminal of the zirconia oxygen sensor 16, a first signal output terminal of the pre-amplifier circuit 43 outputs an amplified oxygen potential signal, a second signal input terminal of the pre-amplifier circuit 43 is connected to a signal output terminal of the first temperature sensor 18 for sensing the temperature of the gas to be measured, and a third signal input terminal of the pre-amplifier circuit 43 is connected to a signal output terminal of the second temperature sensor 20 for measuring the room temperature. The input end of the A/D conversion module 44 is connected to the output end of the preamplifier circuit 43, the input end of the central processing unit 46 is connected to the output end of the A/D conversion module 44, and the display module 48 is controlled by the central processing unit 46 to digitally display the oxygen potential signal.

the signals from the respective sensors are amplified by the pre-amplification circuit module 43 for subsequent processing, the analog signals from the pre-amplification circuit module 43 are converted into digital signals by the a/D conversion module 44, the digital signals can be processed by the cpu 46 for subsequent operations, and the processed digital signals can be displayed on the display module 48 by the cpu 46, whereby the magnitude of the oxygen potential signal can be visually displayed.

Here, the signal processing and control system 40 further includes a temperature control module 50 that controls the temperature of the zirconia oxygen sensor, and the temperature control module 50 controls the temperature of the zirconia oxygen sensor 16 based on the temperature signal of the first temperature sensor 18. Since the operating temperature of the oxygen sensor of the zirconia oxygen sensor is generally 6 ℃ (about ° c, too high or too low temperature will affect the measurement accuracy of the zirconia oxygen sensor, the oxygen sensor of the zirconia oxygen sensor needs to be heated and controlled to operate in the optimal temperature range.

The signal processing and control system 40 of the oxygen sensor 10 of the present invention further comprises a data selection module 52, wherein the data selection module 52 is disposed between the pre-amplification circuit module 43 and the a/D conversion module 44, and is used for selectively inputting the analog signal from the pre-amplification circuit module 43 to the a/D conversion module 44. For example, when measuring the temperature of the gas to be measured, it is necessary to simultaneously acquire the temperature signal of the first temperature sensor 18 and the oxygen potential signal of the zirconia oxygen sensor 16, and the temperature signal and the oxygen potential signal may be selected by the data selection module 52 so as to determine which of the two is a/D converted at a certain time.

The signal processing and control system 40 of the oxygen sensor 10 according to the present invention further includes a power module 54, wherein the power module 54 provides operating voltages to the various modules of the signal processing and control system 40. That is, the power module 54 provides the operation voltage for the pre-amplifier circuit module 43, the a/D conversion module 44, the central processing unit 46, the display module 48, the data selection module 52 and other modules of the signal processing and control system 40. The working voltages of the modules can be the same or different. Here, the power module 54 may be designed to include a toroidal transformer, and a filtering and isolating device is added to both the power input side and the current output side, so as to effectively filter or reduce the interference of the industrial field interference source to the oxygen measurement control device.

Signal processing and control system 40 of oxygen transmitter 10 of the present invention may further comprise a standard current signal module 56, wherein an input of standard current signal module 56 is coupled to central processor 46 and outputs a standard current signal. The standard current signal may be used for external output or for driving other components, or may be converted into a voltage signal for outputting the voltage signal or driving other components. The standard current signal module 56 may include an opto-isolator for receiving the oxygen potential signal from the central processing unit, a D/a converter for converting the oxygen potential signal into an analog signal, and a V/I converter for converting the voltage analog signal into a standard current signal and outputting the standard current signal.

The signal processing and control system 40 adopts a closed-loop control system which is formed by taking a 51-series single chip microcomputer as a core. The input end is an oxygen potential signal, a temperature potential signal and a room temperature potential signal. The output end is a direct current signal of 0mA-10mA or 4mA-20mA generated by the standard current signal module 56. Millivolt-level oxygen potential signals and temperature signals are amplified by the preamplification circuit module 43 and then are connected to the data selection module 52, the data selection module 52 performs data selection on the signals and outputs the signals to the input end of the A/D conversion module 44, the data signals output from the A/D conversion module 44 are connected to the input end of the central processing unit 46 through the buffer, and the central processing unit 46 reads data and calculates corresponding temperature values and oxygen values. The oxygen amount value calculated by the central processing unit 46 is output to the standard current signal module 56, the optical coupler isolator of the standard current signal module 56 performs optical coupler isolation on the digital signal and then inputs the digital signal to the D/A converter, the data is converted into an analog signal, and the analog signal is converted into current signals of 0mA-10mA and 4mA-20mA through the V/I converter and then output. In addition, the temperature signal and the oxygen amount signal calculated by the cpu 46 may be simultaneously outputted to the display module 48 to control the 4-bit LED to display the measurement result, but of course, an LCD display or other types of displays may be used herein.

When designing the sealed box 12, the calibration potentiometer 42 of the signal processing and control system 40 can be installed on the display panel of the housing 14 for non-explosion-proof products, and the box cover of the sealed box 12 is opened to realize on-site calibration. For explosion-proof products, a mechanical calibration device 60 penetrating through the sealed box 12 can be arranged to mechanically adjust the calibration potentiometer 42 of the signal processing and control system 40, so as to achieve the purpose of on-site online calibration of the signal processing and control system 40 without opening the box cover of the sealed box 12.

In addition, aiming at the problem of complex industrial field environment, the invention adds a filtering and isolating design on the power module and the output module when designing the circuit control system, adopts a display driving module which is not easy to be interfered by high-power equipment to cause locking when designing the display module, and can achieve the purpose of effectively reducing the interference fault of the oxygen transducer by the targeted anti-interference design.

the oxygen transmitter of the invention adopts the mechanical calibration device, and the oxygen transmitter can be adjusted without opening the box body cover, so that the display window part only needs to adopt common explosion-proof glass meeting the relevant explosion-proof standard, thereby greatly reducing the production cost. Because mechanical calibration device sets up on oxygen volume changer's sealed box, can operate mechanical calibration device in the outside of sealed box, consequently make the convenient high efficiency of online calibration process. When the non-explosion-proof zirconia oxygen transducer is subjected to explosion-proof design, an explosion-proof touch screen is not needed to change the design of the original oxygen transducer, and the requirement of the oxygen transducer on explosion-proof performance can be met.

it should also be noted that, in the case of the embodiments of the present invention, features of the embodiments and examples may be combined with each other to obtain a new embodiment without conflict.

the above embodiments are merely specific examples of the present invention, but the scope of the present invention is not limited thereto, and the scope of the present invention is defined by the claims.