CN201000382Y - Novel vacuum gauges - Google Patents
Novel vacuum gauges Download PDFInfo
- Publication number
- CN201000382Y CN201000382Y CNU2007201179457U CN200720117945U CN201000382Y CN 201000382 Y CN201000382 Y CN 201000382Y CN U2007201179457 U CNU2007201179457 U CN U2007201179457U CN 200720117945 U CN200720117945 U CN 200720117945U CN 201000382 Y CN201000382 Y CN 201000382Y
- Authority
- CN
- China
- Prior art keywords
- vacuum gauge
- vacuum
- oxygen sensor
- circuit
- pressure
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 239000001301 oxygen Substances 0.000 claims abstract description 106
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 106
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 105
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims abstract description 46
- 239000007789 gas Substances 0.000 claims description 55
- 238000005259 measurement Methods 0.000 claims description 36
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 6
- 238000006243 chemical reaction Methods 0.000 claims description 3
- 239000004973 liquid crystal related substance Substances 0.000 claims description 3
- 229910052697 platinum Inorganic materials 0.000 claims description 3
- 230000001960 triggered effect Effects 0.000 claims description 2
- 238000000034 method Methods 0.000 description 9
- 238000009530 blood pressure measurement Methods 0.000 description 6
- 150000002500 ions Chemical class 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- 230000003071 parasitic effect Effects 0.000 description 4
- 230000006835 compression Effects 0.000 description 3
- 238000007906 compression Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000001819 mass spectrum Methods 0.000 description 3
- 230000005855 radiation Effects 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000002955 isolation Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000011088 calibration curve Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000005489 elastic deformation Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000007667 floating Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000005339 levitation Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 238000000386 microscopy Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- -1 oxygen ions Chemical class 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 230000002285 radioactive effect Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 230000008646 thermal stress Effects 0.000 description 1
Images
Landscapes
- Measuring Fluid Pressure (AREA)
Abstract
The utility model relates to a novel vacuum meter, which comprises a zirconia oxygen sensor for converting the partial oxygen pressure in vacuum into electrical signal to output, and a measuring circuit unit for measuring and controlling according to the electrical signal output by the zirconia oxygen sensor. The novel vacuum meter of the utility model has the advantages that the measuring range is wide, the measuring accuracy is high, the equipment is simple and the cost is low, and simultaneously the utility model can expand the application area of the vacuum meter through accurately measuring the partial oxygen pressure in the vacuum.
Description
Technical Field
The utility model relates to a measure gaseous instrument, more specifically say, relate to a novel vacuum gauge.
Background
Vacuum measurement is a measure of the degree of vacuum, which refers to the degree to which a gas is lean below atmospheric pressure, expressed as pressure. The vacuum measurement comprises three parts of full pressure measurement, partial pressure measurement and vacuum gauge calibration. The instrument used to detect the pressure of the rarefied gas in the low pressure space is called a vacuum gauge. The vacuum gauges are various in types and different in working principle, and except for few which are used for directly measuring pressure, other vacuum gauges are almost used for indirectly measuring pressure. The measured gas is mostly mixed gas except for a few cases. The pressure measurement is generally referred to as a mixed gas full pressure measurement. Partial pressure measurement is becoming increasingly important in modern vacuum measurement techniques. Partial pressure measurement refers to measuring the partial pressure of each component of the mixed gas.
The types of vacuum gauges on the market at present are generally classified according to a vacuum degree calibration method of the vacuum gauge and a measuring principle of the vacuum gauge.
Classified according to the vacuum degree calibration method, the vacuum gauge includes the following two types:
(1) absolute vacuum gauge: the gas pressure is read directly and its pressure response (scale) can be calculated from its own geometry or determined from the force measurements. The absolute vacuum gauge is accurate to all gases and has no relation with the types of the gases, and belongs to a U-shaped tube pressure gauge, a compression type vacuum gauge, a thermal radiation vacuum gauge and the like.
(2) Relative vacuum gauge: the pressure is determined by some quantity which is a function of the gas pressure and cannot be calibrated by simple calculation, calibration being necessary. The relative vacuum gauge generally consists of a sensor (also called a gauge tube or gauge head) and a measurement circuit unit for measurement control. The readings are related to the gas species. There are many types of relative vacuum gauges, such as thermal conduction vacuum gauges and ionization vacuum gauges.
The vacuum gauge is classified according to the vacuum gauge measuring principle, and the vacuum gauge is classified into a direct measuring vacuum gauge and an indirect measuring vacuum gauge.
A direct measurement vacuum gauge that directly measures force per unit area, comprising two of:
(1) static liquid level vacuum gauge: and measuring the pressure by utilizing the liquid level difference of the two ends of the U-shaped pipe.
(2) Elastic element vacuum gauge: the magnitude of the pressure value is measured by the elastic deformation of the surface of the container connected with the vacuum under the action of the pressure.
Indirect measuring vacuum gauge, when the pressure is 10-1At Pa, acting at 1cm2The force on the surface is only 10-5N, it is obvious that it is difficult to measure such a small force, so that the change in pressure can be indirectly measured from the change in physical quantity related to the gas pressure at a low pressure. The vacuum gauges belonging to this category are the following:
(1) a compression type vacuum gauge: the principle is to apply Boyle's law on the basis of the U-shaped tube, i.e. a certain amount of gas with pressure to be measured is subjected to isothermal compression to increase the pressure so as to be measured by a U-shaped tube vacuum gauge, and then the measured pressure is calculated by using the relation between the volume and the pressure.
(2) A heat conduction vacuum gauge: it is made by using the principle that gas heat conduction under low pressure is related to pressure. Commonly used are resistance vacuum gauges and thermocouple vacuum gauges.
(3) Thermal radiation vacuum gauge: the principle that gas heat radiation under low pressure is related to pressure is utilized.
(4) Ionization vacuum gauge: the principle that gas molecules are collided and ionized by energetic particles under low pressure to generate ion current which changes along with the pressure is utilized. Such as: hot cathode ionization vacuum gauges, cold cathode ionization vacuum gauges, and radioactive ionization vacuum gauges, among others.
(5) A discharge tube indicator: the determination of the degree of vacuum, which is generally only a qualitative measure, is made by the gas discharge behavior and the pressure-dependent properties of the discharge color.
(6) A viscous vacuum gauge: the momentum exchange between the gas and the container wall under low pressure, i.e. the external friction principle, is utilized. Such as diaphragm vacuum gauges and magnetic levitation rotor vacuum gauges.
(7) Field microscopy: the pressure is calculated as the adsorption and desorption time versus pressure.
(8) Mass spectrum vacuum gauge: and measuring the partial pressure of the mixed gas by using a mass spectrum technology.
The existing partial pressure vacuum gauges belong to ionization type, namely, gas is ionized firstly, then obtained ions of each component are accelerated, then the ions are introduced into an analyzer, the ions are separated, and the ion current intensity of each component is measured respectively, so that the components and the quantity of the gas can be known. The analyzer can be magnetic, electric, electromagnetic, etc. Commonly used are quadrupole mass spectrometers, gyrometer and radio frequency mass spectrometers.
In the existing vacuum measurement, except for a few direct measurements, most of the measurements are indirect measurements, namely, a certain physical phenomenon is caused in the measured gas firstly, and then a physical quantity related to the pressure in the process is measured, so that a pressure value is determined. This is a characteristic of vacuum measurement, and therefore causes the following problems:
(1) the relationship between any particular physical phenomenon and pressure is most pronounced within a certain pressure range beyond which the relationship becomes weaker. Thus, any method has a certain measurement range, which is the "range" of the vacuum gauge. Existing vacuum gauges all operate within a certain measurement range.
(2) The pressure range involved in modern vacuum technology is as wide as 19 orders of magnitude (10)5～10-14pa), none of the existing vacuum gauges is capable of measuring such a wide pressure range,therefore, several vacuum gauges are always used to respectively control certain areas. However, due to the difference in principle between the vacuum gauges, a large error is often caused in the area where the vacuum gauges are connected with each other.
(3) A certain physical phenomenon is caused in a measured space, and the problem also occurs that from the measurement perspective, a simple physical phenomenon is needed, but a series of parasitic phenomena are inevitably brought in some cases, and the parasitic phenomena bring errors to the measurement, and sometimes make the measurement "noisy", and completely cover the main phenomenon. In order to improve the performance of the vacuum gauge and improve the vacuum measurement accuracy, the main phenomenon must be highlighted to suppress the parasitic phenomenon.
(4) The modern partial pressure vacuum gauge is a special small-sized mass spectrometer, namely a vacuum mass spectrometer, and has strong functions, and the measurement range is 10-1-10-14pa, but the equipment is complex, the price is high, the application field is limited, and the defects are that.
SUMMERY OF THE UTILITY MODEL
The to-be-solved technical problem of the utility model lies in, to the above-mentioned defect of prior art, a novel vacuum gauge is provided.
The utility model provides a technical scheme that its technical problem adopted is: a novel vacuum gauge is constructed, and is characterized by comprising a zirconia oxygen sensor for converting oxygen partial pressure in vacuum into electric signals to be output and a measuring circuit unit for carrying out measurement control according to the electric signals output by the zirconia oxygen sensor.
In the novel vacuum gauge of the present invention, the zirconia oxygen sensor comprises an oxygen concentration cell, and porous platinum electrodes are disposed on both inner and outer sides of a zirconia element of the oxygen concentration cell.
In the novel vacuum gauge of the present invention, the measurement circuit unit includes a calibration module for calibrating the zirconia oxygen sensor.
In the novel vacuum gauge, the measuring circuit unit comprises a main circuit board and an operation display circuit board connected with the main circuit board through a cable.
Novel vacuum gauge in, main circuit board includes direct current constant voltage power supply return circuit, carries out the temperature control return circuit, oxygen sensor signal conversion circuit, operation control processing circuit, standard current signal output circuit and output alarm signal's three routes relay contact output circuit that control to the oxygen sensor temperature.
Novel vacuum gauge in, operation display circuit board includes function button and circuit, liquid crystal display module and drive circuit, emitting diode display circuit and button stereo set suggestion circuit.
In the vacuum gauge of the present invention, the temperature control loop of the oxygen sensor adopts a PID temperature control algorithm and a zero-crossing triggered symmetrical full-wave power output.
In the novel vacuum gauge of the present invention, the measurement circuit unit further includes an optional component for providing air or taking a vacuum environment with a known oxygen partial pressure as a reference gas of the oxygen sensor.
Implement the novel vacuum gauge has adopted technical means such as zirconia oxygen sensor and calibration, has following beneficial effect:
(1) the measuring range is wide. The vacuum gauge measures the oxygen partial pressure range and completely covers and exceeds the pressure range 10 involved in the modern vacuum technology5～10-14pa。
(2) The measurement precision is high. The existing vacuum gauges measure a certain area respectively, but due to the difference of the measurement principle of various vacuum gauges, large errors are often caused in the areas which are mutually connected. This problem can be solved to the vacuum gauge, simultaneously because the measurement principle Nernst equation has the physics certainty of ideal, also improves the measured data accuracy greatly.
(3) The measurement principle Nernst equation that the vacuum gauge adopted has the simplicity of ideal, only has the selectivity to oxygen, and outstanding main phenomenon suppresses the parasitic phenomenon, has improved measurement accuracy.
(4) Compared with the existing mass spectrum vacuum meter for measuring the pressure, the device is simple and the cost is low.
(5) Measuring circuit unit of vacuum gauge is through calibrating zirconia oxygen sensor, ensures measured data's accuracy.
(6) The vacuum gauge can regard the air as oxygen sensor's reference gas except that, still can regard the vacuum environment of known oxygen partial pressure as oxygen sensor's reference gas, and the differential pressure that oxygen sensor both sides bore like this can reduce, improves the performance of vacuum gauge.
(7) The application field of the vacuum gauge can be expanded by accurately measuring the oxygen partial pressure in the vacuum, and the total pressure can be converted when the proportion of the oxygen component in the mixed gas is determined (air evacuation and the like).
Drawings
The invention will be further explained with reference to the drawings and examples, wherein:
fig. 1 is a schematic block diagram of the novel vacuum gauge of the present invention.
Detailed Description
As shown in fig. 1, a novel vacuum gauge includes a zirconia oxygen sensor and a measurement circuit unit.
Wherein, the zirconia oxygen sensor comprises an oxygen concentration cell, and porous platinum electrodes are arranged on the inner side and the outer side of a zirconia element of the oxygen concentration cell.
The zirconia oxygen sensor has the function of changing the oxygen partial pressure in the measured vacuum into an electric signal according to the Nernst equation, and the relation between the output electric signal of the oxygen sensor and the oxygen partial pressure is logarithmic.
The potential value output by the oxygen concentration cell satisfies the following data equation, i.e., Nernst equation, in a certain temperature range:
p1 is the partial pressure of oxygen in the reference gas (air) on one side of the oxygen concentration cell (i.e., the reference gas side), P2 is the partial pressure of oxygen in the gas under test (vacuum) on the other side of the oxygen concentration cell (i.e., the gas under test side), R is the gas constant, F is the faraday constant, and T is the absolute temperature (i.e., T273 + T ℃).
When the oxygen partial pressure of the vacuum gas on the reference gas side (air) and the gas side to be measured is different, oxygen ions migrate from the high side to the low side, establishing an oxygen concentration potential. The output of the oxygen concentration difference potential reflects the oxygen partial pressure value in the measured gas according to the logarithmic rule. During measurement, values of the temperature T and the oxygen concentration potential mV are obtained through measurement, meanwhile, the oxygen partial pressure of a reference gas (air) is known, and the value of P2 (namely the oxygen partial pressure in the measured vacuum gas) can be calculated by substituting the oxygen partial pressure P1, the temperature T and the oxygen potential mV of the reference gas into the equation.
In the Nernst equation, there is a parameter of temperature T, and in general, the temperature T must be higher than 650 ℃, that is, the absolute temperature T is higher than 650+273 ═ 923K, and the oxygen sensor can normally work. If the oxygen sensor is directly inserted into vacuum, the oxygen sensor does not need to be heated when the temperature in the vacuum can meet the condition of being higher than 650 ℃, otherwise, the oxygen sensor needs to be heated for controlling the temperature. Thus, heater components, typically a temperature thermocouple and an electric heater, are included within the oxygen sensor.
The measuring circuit unit is specially designed according to the requirement of measuring the vacuum of the zirconia oxygen sensor. The measuring circuit unit comprises a main circuit board and an operation display circuit board connected with the main circuit board through a cable. The circuits in the main circuit board and the operation display circuit board are uniformly controlled and processed by a microprocessor (single chip microcomputer), the functions are intelligent, and anti-interference measures such as software WATCHDOG (WATCHDOG), electrical isolation, power filtering and the like are adopted.
The main circuit board comprises a direct-current stabilized voltage supply circuit, an oxygen sensor temperature control circuit for controlling stability, an oxygen sensor signal conversion circuit, an operation control processing circuit (a single chip microcomputer), a standard current signal output circuit and a three-way relay contact output circuit (control and alarm) for outputting an alarm signal when the vacuum gauge or the oxygen sensor fails.
The operation display circuit board comprises function keys and a circuit, a liquid crystal display module and a driving circuit, a light emitting diode display circuit and a key sound prompting circuit.
Because the zirconia oxygen sensor has the reasons of material, structure, manufacturing process, aging in the using process and the like, the relation between the output electric signal of the oxygen sensor and the oxygen partial pressure has different degrees of deviation from the Nernst equation, but the basic logarithmic relation is determined, so the sensor needs to be calibrated.
One of the important functions of the measurement circuit unit of the present invention is to have a calibration module that calibrates the zirconia oxygen sensor. The system is calibrated through one or two gas environments (normal pressure environment or vacuum environment) with different known oxygen partial pressure values, and a calibration curve corresponding to the oxygen sensor is obtained through calculation of a vacuum gauge during calibration. During the calibrated measurement process, the vacuum gauge calculates the oxygen partial pressure based on the calibrated oxygen sensor curve, and the accuracy of the measured data is ensured.
Since the oxygen sensor needs to operate at a high temperature, temperature control of the oxygen sensor is required. The utility model discloses according to the needs of difference, the control temperature value and the control mode of optional difference have adopted PID (proportion, integral, differential) temperature control algorithm and zero passage trigger's symmetry full wave power output, have improved control accuracy, have reduced the inside thermal stress of zirconia simultaneously, have prolonged oxygen sensor's life-span. When the oxygen sensor is overheated, the vacuum gauge is provided with a special relay to cut off the heating power supply, thereby protecting the oxygen sensor from being burnt out.
When the vacuum gauge controls the temperature of the oxygen sensor, the vacuum gauge has the functions of fault power-off protection and alarm. In addition the vacuum gauge still has the self-checking performance, can report to the police and show when vacuum gauge or oxygen sensor break down, indicate out the reason to through relay contact output alarm signal. When the vacuum degree is higher or lower than the preset value, the vacuum gauge gives an alarm and displays the alarm, and an alarm signal is output through a relay contact.
In addition, the system can be controlled by selecting control parameters, various data ranges and other functions by operating the function keys of the display circuit board. The common methods include reference gas oxygen partial pressure, output current types and corresponding ranges, alarm limits, calibration vacuum degree values, single-point calibration processes, two-point calibration processes and the like. The user can also select functions such as temperature control, temperature control mode, measurement operation mode and factory data recovery through the dial switch on the mainboard, and can calibrate input and output of the vacuum gauge circuit. And all of these panel operation settings are given in the form of menus.
In addition, as can also be seen from the Nernst equation, since the output electrical signal of the oxygen sensor is logarithmically related to the ratio of the measured gas oxygen partial pressure to the reference gas oxygen partial pressure, a reference gas with a known oxygen partial pressure must be provided on one side (i.e., the reference side) of the zirconia oxygen sensor core element, and the other side (i.e., the measured gas side) contacts the measured gas space. The vacuum gauge, the reference side both can directly link to each other with air circumstance, also can link to each other with the vacuum environment of another known oxygen partial pressure.
The vacuum gauge can regard the air as oxygen sensor's reference gas, still can regard the vacuum environment of known oxygen partial pressure as oxygen sensor's reference gas, makes the differential pressure reduction that oxygen sensor both sides bore, improves the performance of vacuum gauge. For this measuring circuit unit sets up reference gas oxygen partial pressure numerical value through operating display circuit board button, and the singlechip is according to the reference gas oxygen partial pressure numerical value operation of setting up by the vacuum oxygen partial pressure of survey, and no matter the reference gas is air or vacuum environment.
When setting up the oxygen partial pressure value of reference gas through the button, the vacuum that the vacuometer shows is vacuum oxygen partial pressure. When a certain value of the percentage of the oxygen component in the vacuum gas mixture is known (for example, when air is vacuumized, the value of the percentage of the oxygen component is about 21%), the ratio coefficient is input, and the vacuum degree displayed by the vacuum gauge is the vacuum full pressure. Vacuum gauge automatic display 105-10-27The Pa oxygen partial pressure or full pressure measuring range is automatic. The vacuum gauge of the utility model adopts the standard current output of 4-20mA (or 0-10mA) for photoelectric isolation, and the load is 600 + 1200 ohm. The standard current output is an active floating output.
As an improvement of the present invention, the vacuum gauge of the present invention may be provided with an optional member inside, and the optional member is used for providing air or using a vacuum environment with a known oxygen partial pressure as the reference gas of the oxygen sensor. Wherein, a reference air pump can be selected as an optional component for providing air as a reference gas for the oxygen sensor.
Although the present invention has been described in terms of embodiments, those skilled in the art will recognize that there are numerous variations and permutations of the present invention as set forth in the claims appended hereto without departing from the spirit of the invention.
Claims (8)
1. The novel vacuum gauge is characterized by comprising a zirconia oxygen sensor for converting oxygen partial pressure in vacuum into an electric signal to be output and a measuring circuit unit for carrying out measurement control according to the electric signal output by the zirconia oxygen sensor.
2. The new vacuum gauge of claim 1, wherein the zirconia oxygen sensor comprises an oxygen concentration cell having porous platinum electrodes disposed on both the inside and outside of the zirconia element.
3. The novel vacuum gauge of claim 1, wherein the measurement circuit unit comprises a calibration module that calibrates the zirconia oxygen sensor.
4. The novel vacuum gauge of claim 1, wherein the measurement circuit unit comprises a main circuit board and an operation display circuit board connected with the main circuit board through a cable.
5. The vacuum gauge as claimed in claim 4, wherein the main circuit board comprises a DC voltage-stabilized power supply circuit, a temperature control circuit for controlling the temperature of the oxygen sensor, an oxygen sensor signal conversion circuit, an arithmetic control processing circuit, a standard current signal output circuit and a three-way relay contact output circuit for outputting an alarm signal.
6. The vacuum gauge as claimed in claim 4, wherein the operation display circuit board comprises function keys and circuits, a liquid crystal display module and driving circuit, a light emitting diode display circuit and a key sound prompting circuit.
7. The novel vacuum gauge of claim 5, wherein the oxygen sensor temperature control loop employs a PID temperature control algorithm and zero-crossing triggered symmetrical full wave power output.
8. The novel vacuum gauge according to any of claims 1-7, characterized in that the measurement circuit unit further comprises an option for providing air or a vacuum environment with a known oxygen partial pressure as a reference gas for the oxygen sensor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2007201179457U CN201000382Y (en) | 2007-01-09 | 2007-01-09 | Novel vacuum gauges |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2007201179457U CN201000382Y (en) | 2007-01-09 | 2007-01-09 | Novel vacuum gauges |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201000382Y true CN201000382Y (en) | 2008-01-02 |
Family
ID=39014786
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2007201179457U Expired - Fee Related CN201000382Y (en) | 2007-01-09 | 2007-01-09 | Novel vacuum gauges |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201000382Y (en) |
-
2007
- 2007-01-09 CN CNU2007201179457U patent/CN201000382Y/en not_active Expired - Fee Related
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2507428C (en) | Hydrogen gas sensor | |
| EP1921445A1 (en) | Hydrogen gas sensor | |
| CN102818635B (en) | Method for improving calibration precision of infrared sensor | |
| CN105628752A (en) | Calibration method of electrochemical sensor | |
| EP1980848B1 (en) | Electrochemical sensor with short-circuiting switch and method of zero-calibration | |
| CN209656657U (en) | A kind of non-maintaining environmental gas online monitoring system | |
| CN106092375B (en) | The method of calibration and tester of airborne equipment surface temperature sensor | |
| CN111323550A (en) | Detection device and method with self-calibration function for measuring concentration of carbon dioxide in atmosphere | |
| US7028530B2 (en) | Gas detector | |
| JP6128772B2 (en) | Chemical analyzer calibration method and chemical analyzer | |
| CN101221082B (en) | Novel vacuometer | |
| Babu et al. | Calibration of MQ-7 and Detection of Hazardous Carbon Mono-oxide Concentration in Test Canister | |
| CN111595910A (en) | Concentration calculation method | |
| CN201000382Y (en) | Novel vacuum gauges | |
| WO2013073213A1 (en) | Water concentration detection device | |
| CN201311407Y (en) | Chemical resistor sensor system capable of compensating temperature and aging effect | |
| CN109142642A (en) | A kind of gas concentration quick sensing device and cognitive method | |
| CN112461458A (en) | Helium concentration detection control device for helium mass spectrometer leak detection test system | |
| CN115060414B (en) | Device and method for providing high-precision pressure standard | |
| CN104425044A (en) | Measurement method of hydrogen concentration by using two different sensors | |
| KR102301888B1 (en) | Temperature conpensation method for calibrating of gas sensor module using change of heater current | |
| Akram et al. | Selection criterion of gauges for vacuum measurements of systems with diverse ranges | |
| JP6073062B2 (en) | Gas detector | |
| CN208818703U (en) | A kind of gas concentration quick sensing device | |
| Ziyu et al. | Study on internal pressure measurement of vacuum interrupter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20080102 Termination date: 20120109 |