CN1017473B - Double-ball cavity practical standard black body - Google Patents

Abstract

The present invention relates to a practical standard black body of a double-ball cavity for a spectrograph. The cavity body is in the shape of the series connection of double balls; the intersecting position of two ball cavities is provided with a cavity hole so that the two ball cavities can be communicated with each other; a cavity opening is arranged on the cavity body of a connecting line of two ball centers and is used as an output window for thermal radiation; a cylindrical outer cover is coaxially arranged outside the cavity body; a sealed space between the cavity opening and the outer cover is filled with melted tin; resistance wires are wound around the outer cover through fusing and casting a mica skeleton. The present invention has the advantages of high radiation rate, uniform blackness, compact structure, small size, good insulating property, easy manufacture, low cost, etc.; the present invention is an ideal practical standard black body suitable for scientific research departments and metrological departments to analyze physical structures and calibrate various low-temperature irradiation sources.

Description

Double-ball cavity practical standard black body

The invention belongs to a kind of Standard Infrared Source that is used for spectrometer.

Aspect the design and actinometry of infrared system, often need to understand the characteristic of radiation source, will be and estimate the characteristic of radiation source with some measurable parameters standard as a comparison.Measuring the equipment of these parameters will calibrate and demarcate as calibrated radiation source with " black matrix ".So-called black matrix can be thermal power transfer the desirable heat radiator of radiation energy exactly to greatest extent, its radiance ε ₀=1.Practical blackbody then is to can be used for actual use, radiance ε ₀Be in close proximity to 1 heat radiator.Because application target is different with accuracy requirement, practical blackbody has various shape.The black matrix that is close most with the present invention is a ball chamber black matrix.Documents is seen Japanese application for a patent for invention " radiation thermometer calibration blackbody furnace " (application number JP50-58514, open day on November 22nd, 1976, document number JP51-134675).

Common ball chamber black matrix primary structure as shown in Figure 1.Fig. 1 is a ball chamber black matrix structural representation, and among Fig. 1,1 is that cavity, 2 is that outer cover, 3 is that resistance wire, 5 is accent for melting matter, 4.

Cavity 1 is general, and integral body is spheroidal with copper, stainless steel or material such as nickel, molybdenum, in cavity is arranged, internal chamber wall or hacking make it to carry out diffuse reflection, or make minute surface and make it total reflection.Outer cover 2 usefulness heat-resistant insulation materials are made, constitute concentric ball with cavity 1, the outside surface of outer cover 2 twines resistance wire 4, is the black matrix heating, wants the inside surface of electrical isolation, outer cover 2 and cavity 1 outside surface to constitute seal cavity between resistance wire 4 and the outer cover 2, be filled with molten matter 3 in it, molten matter 3 is selected different metals according to different temperature standards, and when utilizing metal molten, the Metal Melting solubility temperature is constant, the assurance cavity temperature is even, and at present known metals such as useful highly purified gold, silver are made molten matter 3.Accent 5 is thermal-radiating exit portal, and its opening diameter should be less than below 1/6 of ball chamber diameter.The blackness of more little this black matrix of opening is high more.But the too little emittance of opening is too low again can not to satisfy the detection requirement, generally selects 1/6～1/10 for moderate, and this black matrix advantage is ε ₀Greatly, radiating surface energy even.But, guaranteeing ε ₀Under the situation, its blackbody chamber has shortcoming, poor practicability such as volume is big, the difficult winding of resistance wire, cost height.

At present, the high speed development of macromolecular material requires the structure of macromolecule product (as petroleum chemicals) is carried out the test analysis of infrared spectrum, improves in order to make the test spectral accuracy, and requiring has the accurate practical blackbody of middle temperature scale about a kind of 500K to make benchmark.Thereby this black matrix is under energy satisfies prerequisite, and the black matrix volume is as much as possible little, could satisfy the request for utilization of spectrometer.

For this reason, the inventor has designed a kind of novel black matrix, and it is little to have a volume, energy emission evenly, radiance ε ₀Height, and be easy to twine characteristics such as resistance wire, reach the purpose of standard utility.

Of the present invention pair of ball chamber standard utility black matrix, cavity are the shape that two hollow balls intersect, i.e. two cavitys that the integrating sphere serial connection forms.The passage that two ball chambeies constitute in the intersection is referred to as lumen pore, and lumen pore communicates two ball chambeies.Have circular accent along the diameter-two ball cavity axis and the cavity joint that connect the two ball centre ofs sphere, as the heat radiation window.The coaxial cylindrical jacket that is surrounded by in the outside of cavity, the outer cover both ends of the surface have round mouth, and a round mouth is relative with accent, and the another side round mouth is for placing sensing element-platinum resistance that thermometric is used.Molten matter is housed in space sealed between cavity and the outer cover, molten matter is 99.99% pure tin, lateral surface at outer cover, be with the casting mica skeleton,, do the skeleton that twines resistance wire with making circular casting mica sheet at the end face of outer cover so that twine the heating resistance wire, make homogeneous heating, because casting mica can machining, make it volume and do very for a short time, can save the electric power of heating simultaneously.Resistive heater has heat-insulation layer outward, and outer felt makes black-body surface and environment temperature close around cooling water pipe again.Be provided with the light hurdle mouth of logical chilled water at the accent place, make emittance on unit area, be tending towards accurate.

Concrete structure can be referring to Fig. 2.Fig. 2 is the sectional view of two ball chambeies standard utility black matrix.Among Fig. 2,1 be cavity, 2 for outer cover, 3 for molten matter, 4 for resistance wire, 5 for accent, 6 for the precision platinum resistance, 7 for lumen pore, 8 for the casting mica skeleton, 9 for heat-insulation layer, 10 for light hurdle mouth, 11 for cooling water pipe, 12 for water delivering orifice, 13 is lead socket, 14 is binding post.

Cavity 1 is two ball chambeies, and available stainless steel is processed into, and accent 5 arrives length at the bottom of the chamber along two centre of sphere lines, and promptly the chamber is long, is slightly less than the diameter sum of two balls, greatly about 80～160mm.The diameter of accent 5 is about 1/6～1/17 of chamber length.Lumen pore that two ball chambeies communicate 7 is for circular, and diameter is about long 1/4 proper in chamber.An end face opened round mouth of cylindrical jacket 2, relative with accent 5, adopt the argon arc welding way cavity 1 and outer cover 2 to be connected into one at accent 2 places; The other end of outer cover 2 is the opened round mouth also, and welds a cylinder in outer cover 2, is used for adorning the accurate platinum resistance 6 of thermometric, and the cylinder bottom is near the outside of cavity 1.Like this, at cavity 1, outer cover 2 and adorn and constitute a sealed space between the cylinder of accurate platinum resistance 6, in the space, charge into molten matter 3.Molten matter 3 can be selected 99.99% simple metal tin for use, black matrix is worked in 370～600K temperature range, and be stabilized in 505K optimality criterion temperature.Casting mica skeleton 8 is enclosed in the lateral surface of outer cover 2 and has two annular casting mica skeletons to place the place, two ends of outer cover 2.Resistance wire 4 twines along the outside groove helically of casting mica skeleton 8, be convenient to fixed position and arrangement rationally, on the casting mica skeleton 8 at two ends, twine resistance wire 4, thereby guarantee the heating-up temperature of molten matter 3 and cavity 1 even everywhere through design rationally along radial direction.For reinforced insulation effect and enhancing add thermal effect, except using casting mica skeleton 8, at the outside surface spraying SiO of outer cover 2 ₂Or Al ₂O ₃Insulation course.Lead socket 13 is multi-receptacle electrical connectors, can be that resistance wire 4, accurate platinum resistance 6 are connected circuit simultaneously.Heat-insulation layer 9 can be selected the alumina-silicate ceramic fibre material for use.Light hurdle mouth 10 is relative with accent 5, so that heat radiation output.Cooling water pipe 11 and water delivering orifice 12 are used to the black matrix cooling, and in the time of at full capacity, skin temperature is no more than environment temperature 5K.

The present invention is owing to replaced ball cavity in the past with two ball cavitys 1, under the diameter of accent 5 condition identical with the ratio of chamber length, has identical substantially radiance, the volume of then two ball chambeies black matrix is 1/4 of a ball cavity volume, volume is suitable for practical for a short time, particularly is applicable to the light source of making spectrometer.The present invention be because the ratio of accent 5 and chamber length can reach 1/12～1/17, and the size of having selected lumen pore 7 again is optimum dimension (chamber grow 1/4), has guaranteed that not only radiation is even, and radiance height (ε is not less than 0.999).The present invention makes black matrix be operated in middle warm area owing to use pure tin to make molten matter, is suitable for use as very much the structure analysis test of macromolecular material, and makes cavity temperature uniform and stable and reduce the cost of manufacture of black matrix.The present invention makes compact overall structure owing to use casting mica skeleton 8 and outer cover 2 surface spraying insulation courses, strengthens to add thermal effect and insulating property, has saved heating power.

In a word, the present invention is that a kind of volume is little, compact conformation, temperature is even, radiance is high novel practical black matrix, can be used as the standard that temperature is measured, demarcate radiation source, determine integral parameter, spectrum parameter and other characteristic of radiation source, can measure the sensitivity of various irradiation devices, be a kind of desirable standard infrared light supply of scientific research and metrological service.

Claims (3)

1, a kind of double-ball cavity practical standard black body that is used for spectrometer, by the cavity that has accent (5) (1), outer cover (2), be wrapped in the resistance wire (4) in outer cover (2) outside and be clipped in cavity (1) and outer cover (2) between the interior molten matter (3) of seal cavity constitute, it is characterized in that, said cavity (1) is two ball chambeies, and intersection, two ball chambeies has lumen pore (7) communicates two chambeies; Said outer cover (2) is columniform, the dead in line of the cylinder axis of outer cover 2 and two ball cavitys (1).

2,, it is characterized in that the outside surface spraying SiO of outer cover (2) according to the described double-ball cavity practical standard black body of claim 1 ₂Or Al ₂O ₃Insulation course; Surround outer cover (2) with casting mica skeleton (8), and go up winding resistance wire (4) at casting mica skeleton (8).

3, according to claim 1,2 described pairs of ball chamber practical blackbodies, the chamber length that it is characterized in that choosing two ball chambeies is in 80～160mm scope, and the diameter of accent (5) is 1/6～1/17 of a chamber length, and the diameter of lumen pore (7) is about 1/4 of chamber length.

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