A kind of air distribution system and method for NOx sensor calibration
Technical field
The present invention relates to a kind of transducer calibration air distribution system and scaling methods, and in particular to one kind is used for nitrogen oxides
The air distribution system and method for transducer calibration.
Background technique
Nitrogen oxides (NOx) sensor for fuel vehicle after-treatment system Tail gas measuring is popped one's head in and is controlled by sensitive ceramic
Module composition, before the use will be by calibration.The calibration of the sensor, refer to by test establish sensor output with
Such a process of relationship between input and the error under determining different use conditions.Any sensor is in manufacture, assembly
After all must to design objective carry out rating test, to guarantee the accurate transmission of magnitude.The calibration of NOx sensor needs
The standard gas source of different certain contents is provided, calibration process is often very long, and the gas of consumption is more, and current distribution system
System is the marked gas for continuing one-way flow, and content is difficult to stablize, and influences the effect of calibration.
Summary of the invention
The present invention provides a kind of air distribution system and method for NOx sensor calibration, it is desirable to provide one kind can
Guarantee marked gas stabilization, gas consumption compared with the air distribution system saved and large-scale production is suitble to use.
The technical scheme to solve the above technical problems is that a kind of distribution for NOx sensor calibration
System, including can be by O2、N2With tri- kinds of gases of NO mixed mixed gas instrument in proportion, the outlet of the mixed gas instrument by pipeline one with
The inlet communication of threeway one, the outlet one of the threeway one on pipeline two and sensing chamber's inlet communication and the pipeline two by setting
There is valve one, the outlet of the sensing chamber is by pipeline three and the inlet communication of threeway two and the pipeline three is equipped with air pump,
The outlet one of the threeway two is connected to emptying pipeline and the emptying pipeline is equipped with valve two, the outlet two of the threeway one
It is connected to the outlet two of the threeway two by circulating line, is equipped with valve close to one end of threeway one on the circulating line
Three, it is equipped with valve four close to one end of the threeway two, the sensing chamber is equipped with several standard specimens for standard transducer insertion
Slot and several detection slots for sensor to be measured insertion.
Based on the above technical solution, the present invention can also be improved as follows.
Further, the pressure sensing for detecting air pressure in corresponding pipeline is equipped on the pipeline one and pipeline two respectively
Device.
The above-mentioned improved benefit of further structure is used to set the biography for detecting its interior air pressure on pipeline one and pipeline two respectively
Sensor, to guarantee that the air pressure in pipeline one is suitably above the air pressure of pipeline two, to guarantee that mixed gas instrument can be indoor to detection in real time
Make-up gas.
Further, the quantity of the standard specimen slot in the sensing chamber is one, the quantity of the detection slot is multiple.
Preferably, the quantity of the detection slot is two.
Use the above-mentioned improved benefit of further structure for the quantity of, detection slot be it is multiple can batch detection it is multiple to be measured
NOx sensor, but the quantity of detection slot is also unsuitable excessive, and otherwise gas leak phenomenon is serious, will affect the standard of cycle detection
True property.
Further, the valve one, valve two, valve three and valve four are electrically operated valve.
Use the above-mentioned improved benefit of further structure for electrically operated valve controllability is good, easy to operate.
The present invention also provides a kind of methods for NOx sensor calibration, utilize above-mentioned air distribution system pair
Nitrogen oxide sensor is demarcated, and is included the following steps:
It initially enters resetting mode: standard transducer and sensor to be measured is inserted into respectively in standard specimen slot and detection slot, so
It opens air pump afterwards and valve one, valve two and valve three is also opened, valve four is closed, lasting suction a period of time, Zhi Daobiao
The reading value of quasi- sensor is stablized constant, then resets completion;
Subsequently into cycle detection mode: valve one and valve three keep it turned on constant, valve two are closed, valve
Four open, while opening mixed gas instrument to the indoor conveying marked gas of detection and keeping it turned on, circulation a period of time to standard
Sensor reading is stablized, and reads corresponding readings and demarcates accordingly to the sensor to be measured in detection slot;
After the completion of primary calibration, mixed gas instrument and valve four is first closed, then open valve two, be again introduced into resetting mode, weight
It is again introduced into cycle detection mode after the completion of setting, opens mixed gas instrument, the marked gas different to another composition of the indoor conveying of detection,
It is demarcated again.
Specifically, the air pressure in pipeline one is greater than the air pressure in the pipeline two in cycle detection mode.
Compared with prior art, the beneficial effects of the present invention are:
The air distribution system and method for nitrogen oxidation transducer calibration provided by the invention are capable of providing the calibration gas for stablizing circulation
Body, marked gas circulate, and relative to the marked gas of traditional one-way flow, more easily guarantee surely detecting its indoor composition
It is fixed, it is high to the accuracy of transducer calibration and gas consumption is greatly saved, it is particularly suitable for large-scale production and uses.
Detailed description of the invention
Fig. 1 provides a kind of structural schematic diagram of air distribution system for NOx sensor calibration for the present invention;
In attached drawing, parts list represented by the reference numerals are as follows:
1, gas instrument is mixed;2, pipeline one;3, threeway one;4, pipeline two;5, valve one;6, sensing chamber;7, pipeline three;8, gas
Pump;9, threeway two;10, pipeline is emptied;11, valve two;12, circulating line;13, valve three;14, valve four.
Specific embodiment
Principles and features of the present invention are described below in conjunction with drawings and the specific embodiments, example is served only for solving
The present invention is released, is not intended to limit the scope of the present invention.
In the description of the present invention, if using the instruction such as "upper", "lower", "left", "right", "top", "bottom", "inner", "outside"
The term in orientation, the orientation or positional relationship of instruction are to be based on the orientation or positional relationship shown in the drawings, and are merely for convenience of
The description present invention and simplified description, rather than the device or element of indication or suggestion meaning must have a particular orientation, with spy
Fixed orientation construction and operation, therefore be not considered as limiting the invention.
As shown in Figure 1, the present invention provides a kind of air distribution system for NOx sensor calibration, including can be by O2、N2
The mixed gas instrument 1 of mixture is carried out with tri- kinds of gases of NO, the outlet of the mixed gas instrument 1 is connected by the import of pipeline 1 and threeway 1
Logical, the outlet one of the threeway 1 is equipped with valve 1 by pipeline 24 and 6 inlet communication of sensing chamber and the pipeline 24,
The outlet of the sensing chamber 6 is by pipeline 37 and the inlet communication of threeway 29 and the pipeline 37 is equipped with air pump 8, described
The outlet one of threeway 29 is connected to emptying pipeline 10 and the emptying pipeline 10 is equipped with valve 2 11, and the threeway 1 goes out
Mouth two is connected to the outlet two of the threeway 29 by circulating line 12, close to one end of threeway 1 on the circulating line 12
Valve 4 14 is equipped with equipped with valve 3 13, close to one end of the threeway 29, the sensing chamber 6 is equipped with several for standard biography
The standard specimen slot of sensor insertion and several detection slots for sensor to be measured insertion.
In one embodiment of the invention, it is equipped with respectively on the pipeline 1 and pipeline 24 for detecting respective tube
The pressure sensor of air pressure in road;The quantity of the standard specimen slot in the sensing chamber 6 is one, the quantity of the detection slot is
It is multiple;The valve 1, valve 2 11, valve 3 13 and valve 4 14 are electrically operated valve.
It should be noted that above-mentioned mixed gas instrument, sensing chamber and standard transducer is commercial product, i.e. the prior art,
Therefore not to repeat here for specific structure and function.
Embodiment 1
Nitrogen oxide sensor is demarcated using above-mentioned air distribution system, is specifically comprised the following steps:
It initially enters resetting mode: standard transducer and sensor to be measured is inserted into respectively in standard specimen slot and detection slot, so
Air pump, valve one, valve two and valve three are opened afterwards, close valve four, lasting suction a period of time (about 5min), until standard
The reading value of sensor is stablized constant, then resets completion;
Subsequently into cycle detection mode: valve one and valve three keep it turned on constant, valve two are closed, valve
Four open, while opening mixed gas instrument and keeping it turned on together to indoor conveying marked gas is detected, O in marked gas one2Contain
The content that amount is 3%, NO is 100ppm, surplus N2, circulation a period of time (about 15s or so), standard transducer stable reading,
Wherein O2Corresponding reading is 3.1%, N2Corresponding reading is 99ppm, reads corresponding readings and accordingly to the sensing to be measured in detection slot
Device is demarcated;
After the completion of above-mentioned calibration, mixed gas instrument and valve four is first closed, then open valve two, be again introduced into resetting mode, it will
The outside pump drainage of gas (about 5min) in sensing chamber and circulating line is again introduced into cycle detection to complete to reset after the completion of resetting
Mode opens mixed gas instrument and the marked gas two different to another composition of the indoor conveying of detection, O in marked gas two2Content is
The content of 5%, NO are 200ppm, surplus N2, circulation a period of time (about 15s or so), standard transducer stable reading, wherein
O2Corresponding reading is 5.6%, N2Corresponding reading is 198ppm, reads corresponding readings and accordingly to the sensor to be measured in detection slot
It is demarcated.
In loop detection process, the air pressure in pipeline one is 0.15MPa, slightly larger than in the pipeline two to sensing chamber's air inlet
Pressure (air pressure be 0.13MPa) in pipeline two, thus guarantee marked gas one after detection room pressure decline in time by
Mixed gas instrument is supplemented, and is guaranteed that marked gas one is detecting indoor air pressure and ingredient stability, is detected Indoor Air in cyclic process
Drops are since pipeline poor sealing and test sample frequently plug replacement and cause.
Embodiment 2
Nitrogen oxide sensor is demarcated using above-mentioned air distribution system, is specifically comprised the following steps:
It initially enters resetting mode: standard transducer and sensor to be measured is inserted into respectively in standard specimen slot and detection slot, so
Air pump, valve one, valve two and valve three are opened afterwards, close valve four, lasting suction a period of time (about 5min), until standard
The reading value of sensor is stablized constant, then resets completion;
Subsequently into cycle detection mode: valve one and valve three keep it turned on constant, valve two are closed, valve
Four open, while opening mixed gas instrument to the indoor conveying marked gas two of detection and keeping it turned on, O in marked gas two2Contain
The content that amount is 10%, NO is 500ppm, surplus N2, circulation a period of time (about 15s or so), standard transducer reading is steady
Determine, wherein O2Corresponding reading is 10.5%, N2Corresponding reading is 490ppm, read corresponding readings and accordingly in detection slot to
Sensor is surveyed to be demarcated;
After the completion of above-mentioned calibration, mixed gas instrument and valve four is first closed, then open valve two, be again introduced into resetting mode, it will
The outside pump drainage of gas (about 5min) in sensing chamber and circulating line is again introduced into cycle detection to complete to reset after the completion of resetting
Mode opens mixed gas instrument and the marked gas two different to another composition of the indoor conveying of detection, O in marked gas two2Content is
The content of 8%, NO are 300ppm, surplus N2, circulation a period of time (about 15s or so), standard transducer stable reading, wherein
O2Corresponding reading is 8.3%, N2Corresponding reading is 295ppm, reads corresponding readings and accordingly to the sensor to be measured in detection slot
It is demarcated.
In loop detection process, the air pressure in pipeline one is 0.18MPa, slightly larger than in the pipeline two to sensing chamber's air inlet
Pressure (air pressure be 0.15MPa) in pipeline two, thus guarantee marked gas two after detection room pressure decline in time by
Mixed gas instrument is supplemented, and is guaranteed that marked gas two is detecting indoor air pressure and ingredient stability, is detected Indoor Air in cyclic process
Drops are since pipeline poor sealing and test sample frequently plug replacement and cause.
The foregoing is merely presently preferred embodiments of the present invention, is not intended to limit the invention, it is all in spirit of the invention and
Within principle, any modification, equivalent replacement, improvement and so on be should all be included in the protection scope of the present invention.