Background technology
High precision extend blackbody infrared origin is as the underlying instrument of infrared test and calibration, and the radiation of outgoing can be full of visual field, convenient calibration and measuring, and can improve and measure and the precision of calibration, and demand is very large, has broad application prospects.Extend blackbody utilizes platinum resistance temperature sensor to carry out temperature control and measurement to radiating surface, the temperature variant voltage of platinum resistance that unbalanced bridge is measured is carried out amplifying rear input A/D convert, utilize the funtcional relationship between resistance and temperature to carry out measuring tempeature by the measurement of resistance, finally in single-chip microcomputer, carry out computing and process.Platinum resistance temperature sensor has the features such as stable performance, reproducible, accuracy is high, temperature-measuring range is large, therefore commercialization extend blackbody is generally the precision of only mark platinum resistance temperature sensor in the index of temperature accuracy both at home and abroad at present, and wherein platinum resistance temperature accuracy determines according to the grade of the platinum resistance adopted.But owing to there is nonlinear relationship between the resistance of platinum resistance and temperature, especially in high temperature section, and the systematic error of resistance measurement and the impact such as lead-in wire, environment temperature, also can bring impact to the temperature measurement accuracy of extend blackbody entire system, therefore be necessary to calibrate the accuracy of extend blackbody complete machine temperature.
Because system of Pt-resistance can be designed to linear system approx, therefore current temperature accuracy calibration steps is the two point calibration method algorithms based on blackbody radiation temperature two-end-point.By adopting measurement standard platinum-resistance thermometer to measure at two end points of extend blackbody control temperature, obtain the true temperature value T of two points for measuring temperature
1and T
2, record self radiation temperature t of corresponding extend blackbody simultaneously
1and t
2, according to linear fit formula:
Calculate correction factor k and b, thus the temperature accuracy within the scope of total temperature is corrected.
Although two point calibration method algorithms of existing technology are simple, operand is little, calibration is convenient, nonlinearity erron is too large, and temperature accuracy calibration accuracy is too poor.
Summary of the invention
Technical matters to be solved by this invention is the calibration steps and the calibration system thereof that provide a kind of surface source blackbody temperature accuracy, and purport in the prior art surface source blackbody temperature adopts the two point calibration algorithms based on blackbody radiation temperature two-end-point to carry out calibrating the problem that precision is too poor in actual applications.
The present invention is achieved in that a kind of calibration steps of surface source blackbody temperature accuracy, wherein, comprises the following steps:
Steps A: choose the individual different base measuring temperature point of M within the scope of extend blackbody design temperature;
Step B: utilize high-precision measurement standard platinum-resistance thermometer to carry out temperature survey by calibration hole to area blackbody radiation source at each base measuring temperature point described, obtain the true temperature value T of each base measuring temperature point
i, record the radiation temperature t of extend blackbody self corresponding to described each base measuring temperature point simultaneously
i;
Step C: the true temperature value that the radiation temperature of the extend blackbody self of each base measuring temperature point described and measurement standard platinum-resistance thermometer are measured is carried out linear fit, and calculates correction factor k
i, b
i;
Step D: utilize described correction factor, surface source blackbody temperature is corrected.
The calibration steps of described surface source blackbody temperature accuracy, wherein, being chosen for of the point of base measuring temperature described in described steps A is chosen in the temperature range of setting.
The calibration steps of described surface source blackbody temperature accuracy, wherein, forms a segmentation between individual different every two points of base measuring temperature point of M described in described steps A, the design temperature of described extend blackbody is divided into some segmentations and calibrates.
The calibration steps of described surface source blackbody temperature accuracy, wherein, calculates correction factor k in described step C
i, b
iformula be:
Wherein, T
ibe the true temperature value of i-th base measuring temperature point, t
ibe the radiation temperature of the extend blackbody self that i-th base measuring temperature point is corresponding, 1≤i≤M-1.
The calibration steps of described surface source blackbody temperature accuracy, wherein, described step D comprises: by 2 multistage linear correcting algorithms, correct the surface source blackbody temperature in each segmentation.
The present invention also provides a kind of calibration system of surface source blackbody temperature accuracy, wherein, comprising:
Base measuring temperature point chosen module, will choose the individual different base measuring temperature point of M within the scope of extend blackbody design temperature;
Temperature-measuring module, be connected with described base measuring temperature point chosen module, utilize high-precision measurement standard platinum-resistance thermometer to carry out temperature survey by calibration hole to area blackbody radiation source at each base measuring temperature point described, obtain the true temperature value T of each base measuring temperature point
i, and record the radiation temperature t of extend blackbody self corresponding to described each base measuring temperature point simultaneously
i;
Computing module, be connected with described temperature-measuring module, the true temperature value that the radiation temperature of the extend blackbody self of each base measuring temperature point measured by described temperature-measuring module and measurement standard platinum-resistance thermometer are measured carries out linear fit, and calculates correction factor k
i, b
i;
Correction module, is connected with described computing module, and the correction factor utilizing described computing module to calculate, corrects surface source blackbody temperature.
The calibration system of described surface source blackbody temperature accuracy, wherein, described base measuring temperature point chosen module also comprises line segment constructing module, described line segment constructing module is used for forming a segmentation by between individual for described M different every two points of base measuring temperature point, the design temperature of described extend blackbody is configured to some segmentations and calibrates.
The calibration system of described surface source blackbody temperature accuracy, wherein, described computing module comprises automatic computing module, and described automatic computing module is by correction factor k
i, b
iformula
Wherein, T
ibe the true temperature value of i-th base measuring temperature point, t
ibe the radiation temperature of the extend blackbody self that i-th base measuring temperature point is corresponding, 1≤i≤M-1 asks for correction factor k automatically
i, b
i.
The calibration system of described surface source blackbody temperature accuracy, wherein, described correction module comprises correcting algorithm module, and described correcting algorithm module, by 2 multistage linear correcting algorithms, corrects the surface source blackbody temperature in each segmentation.
The calibration steps of a kind of surface source blackbody temperature accuracy based on 2 multistage linear correcting algorithms of calibration steps of a kind of surface source blackbody temperature accuracy that the present invention proposes, in total temperature scope internal calibration extend blackbody radiation temperature, improve the temperature accuracy of complete machine, and trace to the source easily, precision is high.
Embodiment
In order to make object of the present invention, technical scheme and advantage clearly understand, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.
The present invention proposes a kind of calibration steps of surface source blackbody temperature accuracy, object is the nonlinearity erron correcting platinum resistance temperature measuring system further, the measuring accuracy of whole system is improved within the scope of total temperature, improve the calibration accuracy of extend blackbody radiation temperature accuracy, meet high precision measurement demand.
The present invention adopts 2 multistage linear correcting algorithms, the scope that arranged by the platinum resistance temperature of extend blackbody is divided into some sections and calibrates, in each section, utilize linear segmented function to approach nonlinear characteristic curve, namely adopt multistage broken line chain to replace true nonlinear curve.By the method corrected in sectional calibration point internal linear, temperature accuracy calibration is carried out to extend blackbody total system, the nonlinearity erron that the non-equilibrium bridge for measuring temperature of further reduction platinum resistance, platinum resistance self and lead resistance etc. are brought, improves surface source blackbody temperature accuracy measuring accuracy.
As shown in Figure 1, a kind of calibration steps of surface source blackbody temperature accuracy, comprises the following steps:
Steps A: choose the individual different base measuring temperature point of M within the scope of extend blackbody design temperature;
Step B: utilize high-precision measurement standard platinum-resistance thermometer to carry out temperature survey by calibration hole to area blackbody radiation source at each base measuring temperature point described, obtain the true temperature value T of each base measuring temperature point
i, record the radiation temperature t of extend blackbody self corresponding to described each base measuring temperature point simultaneously
i;
Step C: the true temperature value that the radiation temperature of the extend blackbody self of each base measuring temperature point described and measurement standard platinum-resistance thermometer are measured is carried out linear fit, and calculates correction factor k
i, b
i; Described correction factor k
iand b
icomputing formula be:
Wherein, T
ibe the true temperature value of i-th base measuring temperature point, t
ibe the radiation temperature of the extend blackbody self that i-th base measuring temperature point is corresponding, 1≤i≤M-1;
Step D: utilize correction factor, is corrected the surface source blackbody temperature in each segmentation by 2 multistage linear correcting algorithms, thus realizes the high-precision calibration of surface source blackbody temperature accuracy within the scope of total temperature.
The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, all any amendments done within the spirit and principles in the present invention, equivalent replacement and improvement etc., all should be included within protection scope of the present invention.