A kind of scaling method of online ozone analyzer
Technical field
The present invention relates to a kind of scaling method, particularly about a kind of scaling method of online ozone analyzer.
Background technology
The troposphere atmospheric ozone is one of important secondary light chemical pollutant that influences atmosphere quality, visibility, aerial oxygen voltinism and health, because its regional influence obviously, cause the concern of environmental administration and environment R﹠D institution gradually, therefore, the observation of troposphere atmospheric ozone also is included in the middle of the daily air quality monitoring system of environmental administration gradually.At present, assay method for ozone concentration has a lot, wherein, sodium indigotindisulfonate spectrophotometric method, ultraviolet spectrophotometry and chemiluminescence fluorescence method are three kinds of ozone analysis determining methods recommending in (GB3095-1996) of China's " ambient air quality " in 1996.And ultraviolet spectrophotometry be most widely used at present, method that technology is the most ripe, its principle is the ultraviolet light that utilizes under the ozone molecule absorption 254nm, according to Lambert-Beer's law, can be directly per sample gas to the ozone concentration in the absorbance log calculation sample gas of ultraviolet light.These class methods need be used online ozone analyzer in implementation procedure, the simple structure of online ozone analyzer, and ruuning situation is stable.But because instrument the excessive situation of drift value can occur after under situations such as carrying, installation, part aging and reaction tank pollution, using certain hour, but drift value is less in time owing to this instrument, often is difficult in the field inspection finding.
In order to guarantee the accurate operation of online ozone analyzer, need regularly it to be demarcated.Traditional scaling method of online ozone analyzer device is to use the standard ozone generator, produce a certain amount of, decide concentration of ozone as standard substance, after squeezing into online ozone analyzer, investigate the difference between input standard value and the instrument readout, investigate the accuracy of online ozone analyzer with this.The principle of ozone generator commonly used is made high-concentrated ozone for using high-voltage arc at present, is made into the output ozone of normal concentration through gas distributing system.Because standard ozone generator cost is higher and carry inconvenience, therefore most environmental administrations and scientific research institution, have restricted the observation effect of online ozone analyzer to a certain extent not to the independent outfit standard ozone generator of online ozone analyzer.
Summary of the invention
At the problems referred to above, the purpose of this invention is to provide a kind of strong operability, low, the accurate real-time height of device therefor cost, be applicable to the scaling method of the online ozone analyzer of field environment observation.
For achieving the above object, the present invention takes following technical scheme: a kind of scaling method of online ozone analyzer, it may further comprise the steps: 1) be provided with one and be used for gas distributing system that online ozone analyzer is demarcated, described gas distributing system comprises Zero gas generator, gas marking apparatus, online nitrogen-oxide analyzer,, online ozone analyzer, NPN calibrating gas steel cylinder and nitrogen monoxide calibrating gas steel cylinder; Be provided with three flow controllers, a mixing bunker and an ozone generating-device in the described gas marking apparatus; Be provided with the thermocatalysis reburner in the described online nitrogen-oxide analyzer; 2) NPN calibrating gas steel cylinder is connected to the gas marking apparatus after, NPN calibrating gas steel cylinder and Zero gas generator are squeezed into gas simultaneously in the gas marking apparatus, in mixing bunker, produce the NPN calibrating gas of deciding the concentration constant flow by the flow controller in the gas marking apparatus, the NPN calibrating gas of deciding the concentration constant flow that produces is driven in the online nitrogen-oxide analyzer,, utilize thermocatalysis reburner in the online nitrogen-oxide analyzer, will decide the oxides of nitrogen that contains in the NPN calibrating gas of concentration constant flow, be converted into nitrogen monoxide; Observe the difference between the nitrogen monoxide value that concentration constant flow NPN calibrating gas value and online nitrogen-oxide analyzer, read of deciding of input, determine that the thermocatalysis reburner is to the transformation efficiency A of the oxides of nitrogen in the NPN calibrating gas in the online nitrogen-oxide analyzer; 3) nitrogen monoxide calibrating gas steel cylinder is connected to the gas marking apparatus after, nitrogen monoxide calibrating gas steel cylinder and Zero gas generator are squeezed into gas simultaneously in the gas marking apparatus, in mixing bunker, produce the nitrogen monoxide calibrating gas of deciding the concentration constant flow by the flow controller in the gas marking apparatus, the nitrogen monoxide calibrating gas of deciding the concentration constant flow that produces is driven in the online nitrogen-oxide analyzer,, the constant flow of observing input decide the difference between the nitrogen monoxide value that concentration nitrogen monoxide calibrating gas value and online nitrogen-oxide analyzer, read, and cooperation transformation efficiency A determines the accuracy of measurement B of online nitrogen-oxide analyzer; 4) ozone generating-device in the unlatching gas marking apparatus, the ability that the ozone that ozone generating-device produces at this moment is set is a%, the span of a is 0~100, produce a certain amount of unknown concentration ozone, this part ozone is squeezed in the online ozone analyzer by flow controller, roughly determined the ozone concentration value C that squeezes into by online ozone analyzer; 5) open nitrogen monoxide calibrating gas steel cylinder, in the gas marking apparatus, squeeze into the nitrogen monoxide calibrating gas, keep ozone generating-device to open simultaneously, enter the ozone concentration that nitrogen monoxide calibrating gas concentration in the mixing bunker and ozone generating-device produce by the flow controller in gas marking apparatus control, wherein, enter nitrogen monoxide calibrating gas concentration in the mixing bunker and need surpass 1~2 times of ozone concentration C that online ozone analyzer roughly determines; Excessive nitrogen monoxide calibrating gas and ozone reaction generate nitrogen dioxide and oxygen, nitrogen dioxide that generates and oxygen and remaining nitrogen monoxide calibrating gas are retained in the mixing bunker in the gas marking apparatus, then the gas in the mixing bunker is directly squeezed in the online nitrogen-oxide analyzer,, write down the content of nitrogen dioxide value that online nitrogen-oxide analyzer, is read, accuracy of measurement B in conjunction with online nitrogen-oxide analyzer,, obtain the accurate concentration value D of nitrogen dioxide, promptly obtaining in the step 4) ozone generating-device is under the situation of a% producing the ozone ability, the exact value D of the ozone concentration of generation; 6) demarcation of online ozone analyzer: the ozone concentration value C that online ozone analyzer in the exact value D of the ozone concentration that obtains in the step 5) and the step 4) is roughly determined compares, and online ozone analyzer is demarcated; 7) return step 4), reset the value of a%, online ozone analyzer is carried out multi-point calibration.
The present invention is owing to take above technical scheme, it has the following advantages: 1, the present invention adopts the common equipment in the field inspections such as environmental administration and R﹠D institution atmospheric contaminant analyzer device commonly used at present, calibrating instrument to form gas distributing system, and adopt common agents to be used for online ozone analyzer is demarcated, and need not the independent outfit standard ozone generator of online ozone analyzer, therefore, not only saved cost, and have strong operability, convenient and swift, accuracy is high, be applicable to characteristics such as field environment observation.2, the present invention is by Zero gas generator and gas marking apparatus and NPN calibrating gas and nitrogen monoxide calibrating gas, can determine the conversion ratio of online nitrogen-oxide analyzer, to the oxides of nitrogen in the NPN calibrating gas, can determine the accuracy of measurement of online nitrogen-oxide analyzer, according to conversion ratio, lay the foundation for accurately demarcating online ozone analyzer.3, the present invention produces a certain amount of unknown concentration ozone by the ozoniferous ability of ozone generating-device in the gas marking apparatus is set, and roughly determines the ozone concentration value by online ozone analyzer; Reaction by nitrogen monoxide calibrating gas in the gas marking apparatus and ozone then, generate nitrogen dioxide and oxygen, accuracy of measurement according to online nitrogen-oxide analyzer,, can accurately measure the accurate concentration value of nitrogen dioxide, promptly obtain the exact value of ozone concentration, the exact value of this ozone concentration compares with the ozone concentration value of roughly determining, can demarcate online ozone analyzer.4, the present invention can be by being provided with in the gas marking apparatus, the ozoniferous different ability values of ozone generating-device, and then can carry out multi-point calibration to online ozone analyzer.The present invention is skillfully constructed, and is easy to operate, and the degree of accuracy height can be widely used in the calibration process of online ozone analyzer.
Description of drawings
Fig. 1 is the gas distributing system synoptic diagram that the present invention is used to demarcate
Embodiment
Below in conjunction with drawings and Examples the present invention is described in detail.
The present invention includes following steps:
1) be provided with one and be used for gas distributing system that online ozone analyzer is demarcated: as shown in Figure 1, this gas distributing system comprises conventional Zero gas generator 1, gas marking apparatus 2, online nitrogen-oxide analyzer, 3, online ozone analyzer 4, NPN calibrating gas steel cylinder 5 and nitrogen monoxide calibrating gas steel cylinder 6.Wherein, Zero gas generator 1 is used for gases such as airborne ozone, carbon monoxide, sulphuric dioxide, oxides of nitrogen are removed, thereby produce the gas of cleaning, and the clean air that produces squeezed in the gas marking apparatus 2, as the balance carrier gas, dilution enters the high concentration calibrating gas in the gas marking apparatus 2, thereby obtains deciding the calibrating gas of concentration, constant flow.Be provided with three flow controllers 21,22 and 23, one mixing bunkers 24 and an ozone generating-device 25 in the gas marking apparatus 2.Be provided with thermocatalysis reburner (not shown) in the online nitrogen-oxide analyzer, 3, effect is that the oxynitrides that will enter in the online nitrogen-oxide analyzer, 3 is converted to nitrogen monoxide.The NPN calibrating gas is one of gas commonly used in the atmosphere environment supervision, and English name is N-propylnitrate, and composition is: n-propyl nitrate, the NPN calibrating gas can directly be bought for demarcating transformation efficiency of the oxides of nitrogen usefulness.
2) measure the transformation efficiency of the oxides of nitrogen of online nitrogen-oxide analyzer, 3: after NPN calibrating gas steel cylinder 5 is connected to gas marking apparatus 2, NPN calibrating gas steel cylinder 5 and Zero gas generator 1 are squeezed into gas simultaneously in gas marking apparatus 2, by the flow controller in the gas marking apparatus 2 21,23 produce the NPN calibrating gas of deciding the concentration constant flow in mixing bunker 24, the NPN calibrating gas of deciding the concentration constant flow that produces is driven in the online nitrogen-oxide analyzer, 3, utilize thermocatalysis reburner in the online nitrogen-oxide analyzer, 3 will decide the oxides of nitrogen that contains in the NPN calibrating gas of concentration constant flow, be converted into nitrogen monoxide; Observe the difference between the nitrogen monoxide value that concentration constant flow NPN calibrating gas value and online nitrogen-oxide analyzer, 3 read of deciding of input, determine the transformation efficiency A of the oxides of nitrogen in 31 pairs of NPN calibrating gas of thermocatalysis reburner in the online nitrogen-oxide analyzer, 3.
3) measurement accuracy of online nitrogen-oxide analyzer, 3 is demarcated: after nitrogen monoxide calibrating gas steel cylinder 6 is connected to gas marking apparatus 2, nitrogen monoxide calibrating gas steel cylinder 6 and Zero gas generator 1 are squeezed into gas simultaneously in gas marking apparatus 2, by the flow controller in the gas marking apparatus 2 21,23 produce the nitrogen monoxide calibrating gas of deciding the concentration constant flow in mixing bunker 24, the nitrogen monoxide calibrating gas of deciding the concentration constant flow that produces is driven in the online nitrogen-oxide analyzer, 3, the constant flow of observing input decide the difference between the nitrogen monoxide value that concentration nitrogen monoxide calibrating gas value and online nitrogen-oxide analyzer, 3 read, and cooperation transformation efficiency A determines the accuracy of measurement B of online nitrogen-oxide analyzer.
4) ozone generating-device 25 in the unlatching gas marking apparatus 2, produce a certain amount of unknown concentration ozone, because design concept, the generation concentration of ozone generating-device 25 does not have the normal concentration design in the gas marking apparatus 2, the number percent design is only arranged, ozone generating-device 25 can ozoniferous maximum capacity be 100%, thousands of approximately ppb concentration, it is a%=30% that this step is provided with ozone generating-device 25 ozoniferous abilities, be that ozone generating-device 25 produces 30% of ozone maximum capacity, but be not limited thereto, the span of a is 0~100, this part ozone is squeezed in the online ozone analyzer 4 by flow controller 22, roughly determined the ozone concentration C that squeezes into by online ozone analyzer 4.
5) open nitrogen monoxide calibrating gas steel cylinder 6, in gas marking apparatus 2, squeeze into the nitrogen monoxide calibrating gas, keep ozone generating-device 25 to open simultaneously, enter the ozone concentration that nitrogen monoxide calibrating gas concentration in the mixing bunker 24 and ozone generating-device 25 produce by the flow controller in the gas marking apparatus 2 23,22 control, wherein, enter nitrogen monoxide calibrating gas concentration in the mixing bunker 24 and need surpass 1~2 times of ozone concentration C that online ozone analyzer 3 roughly determines.Excessive nitrogen monoxide calibrating gas and ozone reaction, generate nitrogen dioxide and oxygen, nitrogen dioxide and oxygen and remaining nitrogen monoxide calibrating gas are retained in the mixing bunker 24 in the gas marking apparatus 2, then the gas in the mixing bunker 24 is directly squeezed in the online nitrogen-oxide analyzer, 3, write down the content of nitrogen dioxide value that online nitrogen-oxide analyzer, 3 is read, in conjunction with the accuracy of measurement B of online nitrogen-oxide analyzer, 3, can obtain the accurate concentration value D of nitrogen dioxide.Because the mol ratio of nitrogen monoxide and ozone reaction is 1: 1, and the amount of generation nitrogen dioxide and the mol ratio of required nitric oxide production amount also are 1: 1, therefore, accurate concentration value D according to content of nitrogen dioxide, can obtain ozone generating-device 25 in the gas marking apparatus 2 is under 30% the situation producing the ozone ability, the accurate concentration value of the ozone that produces, promptly the accurate concentration value D with nitrogen dioxide is identical.
6) demarcation of online ozone analyzer: the ozone concentration value C that online ozone analyzer 4 in the accurate concentration value D of the ozone that obtains in the step 5) and the step 4) is roughly determined compares, and online ozone analyzer 4 is demarcated.
7) owing to the ozone generating-device 25 that has accurately obtained in the gas marking apparatus 2, it in ozoniferous ability the ozone concentration under 30% the situation, therefore, can return step 4), reset ozone generating-device 25 ozoniferous ability a%, for example a%=10%, a%=50% etc., determine the exact value of the ozone concentration of generation under the different ability conditions, therefore can very easily carry out multi-point calibration, thereby determine the degree of accuracy of online ozone analyzer 4 accurately online ozone analyzer 4.
The contrast of the inventive method and traditional scaling method is compared:
In order to verify the accuracy of the inventive method, by using this method and standard ozone generator (49PS) to contrast in the field inspection at the scene, comparing result shows, this method calibrated error can satisfy in the field inspection calibration request to online ozone analyzer fully between 1%~3%.
The various embodiments described above only are used to illustrate the present invention, and wherein the structure of each parts, connected mode etc. all can change to some extent, and every equivalents of carrying out on the basis of technical solution of the present invention and improvement all should not got rid of outside protection scope of the present invention.