GB2095903A - Thermoelectric arrangement for measuring the radiation energy of an electromagnetic radiation source - Google Patents
Thermoelectric arrangement for measuring the radiation energy of an electromagnetic radiation source Download PDFInfo
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- GB2095903A GB2095903A GB8202934A GB8202934A GB2095903A GB 2095903 A GB2095903 A GB 2095903A GB 8202934 A GB8202934 A GB 8202934A GB 8202934 A GB8202934 A GB 8202934A GB 2095903 A GB2095903 A GB 2095903A
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- arrangement
- thermal
- radiation
- laminas
- thermo
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- 230000005855 radiation Effects 0.000 title claims abstract description 80
- 230000005670 electromagnetic radiation Effects 0.000 title claims abstract description 17
- 241000761557 Lamina Species 0.000 claims abstract description 32
- 239000006096 absorbing agent Substances 0.000 claims abstract description 18
- 238000011156 evaluation Methods 0.000 claims description 15
- 239000000463 material Substances 0.000 claims description 4
- 239000004020 conductor Substances 0.000 claims description 3
- 239000011810 insulating material Substances 0.000 claims description 2
- 238000003491 array Methods 0.000 abstract description 3
- 238000005259 measurement Methods 0.000 description 14
- 238000004519 manufacturing process Methods 0.000 description 4
- 238000001514 detection method Methods 0.000 description 3
- 238000012935 Averaging Methods 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 238000004020 luminiscence type Methods 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 239000011358 absorbing material Substances 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000009529 body temperature measurement Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000012777 electrically insulating material Substances 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000005693 optoelectronics Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 238000013214 routine measurement Methods 0.000 description 1
- 230000005676 thermoelectric effect Effects 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
- 239000002966 varnish Substances 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J1/00—Photometry, e.g. photographic exposure meter
- G01J1/02—Details
- G01J1/04—Optical or mechanical part supplementary adjustable parts
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J1/00—Photometry, e.g. photographic exposure meter
- G01J1/02—Details
- G01J1/04—Optical or mechanical part supplementary adjustable parts
- G01J1/0407—Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings
- G01J1/0437—Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings using masks, aperture plates, spatial light modulators, spatial filters, e.g. reflective filters
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J1/00—Photometry, e.g. photographic exposure meter
- G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
- G01J1/4257—Photometry, e.g. photographic exposure meter using electric radiation detectors applied to monitoring the characteristics of a beam, e.g. laser beam, headlamp beam
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
- G01J5/10—Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors
- G01J5/12—Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors using thermoelectric elements, e.g. thermocouples
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
- H10N10/10—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects operating with only the Peltier or Seebeck effects
- H10N10/17—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects operating with only the Peltier or Seebeck effects characterised by the structure or configuration of the cell or thermocouple forming the device
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Optics & Photonics (AREA)
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
- Investigating Or Analyzing Materials Using Thermal Means (AREA)
Abstract
An arrangement operating on the calorimetric principle for measuring the radiation 9 of electro-magnetic radiation sources includes sensing elements each constituted by an absorber element 1, a plurality of thermo-electric elements 2,2' and a thermal reservoir 3. The thermo-electric elements are arranged in substantially annular external and internal arrays 4,5 and are in the form of laminas connected via thermal resistor bridges (6). The absorber element (1) is thermally connected to each individual lamina of the internal annular array. The external annular array is thermally connected to and electrically insulated from the thermal reservoir. <IMAGE>
Description
SPECIFICATION
Arrangement for measuring the radiation energy of an electromagnetic radiation source
The present invention relates to an arrangement for measuring the radiation energy of a continuously operating or pulsating electromagnetic radiation source operating on the calorimetric principle, and particularly for measuring both the entire energy emitted from an electromagnetic radiation source and the energy distribution across a beam cross-section remote from the radiation source.
The invention is particularly for use in lasers, but can also be used in special radiation sources such as luminescence diodes. The calorimetric measuring arrangement permits the use in a fast, economic and serial performance for routine measurements in quality tests and checking of radiation sources in scientific and research applications.
In many technical fields, in research and development in the production of scientific apparatus it is very often necessary to have a safe and quick checking of the quality of an electromagnetic radiation source and of the radiation emitted. This is particularly the case with series production.
A main feature of the quality of the radiation properties is, apart from the entire energy of the radiation, the radiation divergence, that is the distribution of the radiation energy over a definite space angle or space angle interval remote from the radiation source.
The detection of both typical values yields an exact and quick determination of the energy contained in a radiation sample. When the energy is measured by the calorimetric principle, the radiation energy, in a first step, is converted into thermal energy and then into a temperature variation which is electrically measured and evaluated.
A conversion into thermal energy requires a nearly complete absorption of the radiation energy independent of the respective wavelength.
Disc or cone shaped absorbers selected from blackened metal, graphite and the like, and volume absorbers suitable for very high radiation powers made of glass are commonly used.
The temperaure increase produced by radiation in said absorbers is measured by thermistors or thermoelectric elements and the results are indicated.
It is important that the measuring precision is independent of the position where a radiation beam impinges upon the absorbing face, and on the energy distribution across a beam cross-section. Therefore, the measurement can only be performed after temperature compensation in the absorber.
During this period the temperature loss due to radiation splitting has to be negligible within the range of the measuring tolerance.
This requires a suitable thermal insulation and a high decay constant of the absorbing material. The decay constant, in turn, determines an optimal measuring sequence.
East German Patent specification No. 62929 discloses an absorber cone provided with a shaft which is connected to a heat reservoir. The temperature balance is attained after a respective period. In the course of operation, a temperature gradient builds up along the entire shaft when the heat sinks to the heat reservoir.
That is, the temperature measurement is delayed until a heat balance is obtained, which is, however, only approximated. It is a disadvantage of said arrangement that not the entire thermal energy flows through the shaft. A portion is radiated to the ambient surroundings which involves random heat losses, and, hence, leads to measuring errors.
East German Patent specification No. 132544 discloses a further solution to obtain an independence on the radiation impingement location and on the intensity distribution across a beam cross-section. To this end a plurality of detectors, such as thermoelectric elements or thermistors, are distributed over an entire face of the absorber.
Both solutions mentioned hereinbefore are disadvantageous since they are technologically difficult to handle.
Concerning an exact energy measurement of high resolution, the factors of ambient radiation and ambient temperature drift restrict the measuring resolution and the applicability of a measuring arrangement.
It is generally known to use a differential arrangement comprised by two absorbers to overcome such disadvantages.
This, however, requires a considerable degree of identity of the two absorbers used with respect to sensitiveness, response time and performance time constant.
This arrangement, in turn, is disadvantageous since the production of two equal absorbers of identical properties requires considerable expenditure on technology, control and calibration.
It is a further disadvantage that the absorber elements are difficult to reproduce in order to have a large number of equal arrangements for energy measurements.
To avoid the more or less expensive calorimetric energy measurement solutions, the radiation divergence has been detected by less complicated arrrangements such as scanning of the radiation cross-section by the use of displaceable or variable apertures. Such arrangements are, for example, disclosed in US-specification
No. 3830571 and in East German patent specification No. 147153, where the energy of the radiation field is "portion-wise" detected. The latter solutions are disadvantageous since they are time-consuming and require a complicated mechanical system for guiding the apertures, apart from not being suitable for measuring individiual radiation pulses. Furthermore, a time consuming averaging unit is required to eliminate measuring errors due to system fluctuations inherent in a radiation source.
Information about the actual quality of the radiation source is not feasible.
US-patent specification No. 4029162 discloses an optoelectronic detecting unit including a detector matrix.
Such a solution is disadvantageous since radiation intensity reducing means are employed which involve interferences, apart from the sophisticated and extensive evaluation electronics. Furthermore, the detector matrix is very expensive.
It is further known to detect the electromagnetic radiation by a photo recording technique and by subsequently analysing the exposed films photometrically.
It is a disadvantage that no reai-time evaluation takes place and, hence, application for series tests of a plurality of radiation sources is not feasible.
It is an object of the present invention to obviate the above disadvantages.
The invention relates to an arrangement operating on the calorimetric principle for measuring the radiation energy of electromagnetic radiation sources, the arrangement including sensing elements comprising an absorber element, a plurality of thermo-electric elements and a thermal reservoir, wherein said plurality of thermo-electric elements is arranged in a substantially annular external and internal array, both of which arrays is electrically and thermally conducting, and the individual thermo-electric elements are laminas which are provided with connection lines to connect the internal laminas to the external laminas via thermal resistance bridges, said individual laminas being series connected to integrate the thermal quantities flowing through the individual laminas, and wherein the absorber element is enclosed by said internal annular array and is thermally connected to each individual lamina, the external annular array being thermally connected to the thermal reservoir and wherein an evaluation unit is electrically connected both to the external and to the internal array of thermo-electric elements.
It is, however, also feasible to arrange the individual laminas on a geometrical shaped base other than said annular arrays. Preferably, the internal and external annular arrangements are provided with the same number of laminas. It depends, however, on the measuring precision required to determine the number of laminas.
It is a further advantage, when the internal and the external laminas and the thermal resistance bridges connecting the former to the latter are printed as circuit paths on a base material selected from thermal and electric insulating material.
Such an arrangement is simple and technologically easy to handle. The heat reservoir is made of any suitable thermally conducting material, the thermal capacity of which is a multiple of the thermal capacity of the thermo-electric elements.
Furthermore, it is feasible to construct the thermo-resistance bridges of resistance wire having electrical and thermal connections to the individual laminas.
The sensing member as disclosed hereinbefore permits the determination of the energy of an electromagnetic radiation source with a considerably high precision and resolution in a comparatively short time.
Furthermore, the present arrangement can be adapted to measure the radiation divergence of a radiation source. To this end at least two of said sensing members are sequentially positioned in a beam emitted from a radiation source. The one absorbing member of said sensing members which is arranged between the
radiation source and the other absorbing member is provided with an aperture in its centre which aperture corresponds, considered from the radiation source, to a definite space angle.
In a further alternative solution provided by the invention, at least three sensing members are employed sequentially positioned in the path of beams emitted by the radiation source and the diameters of the
apertures in said absorber elements are reduced with an increased distance from the radiation source. This
permits the detection of the energy distribution in several space angles. The sensing members are provided with electrically conductive connections to a central evaluation unit for on-line evaluation and indication of the detected measuring values, in addition to their inherent evaluation unit.
By virtue of the new arrangement, both a single and a series investigation and measurement of the
radiation energy emitted from an electromagnetic radiation source, for example, a luminescence diode, or
pulsed or cw-lasers is quickly feasible with the required position.
The simultaneous determination of the entire energy and the radiation divergence permits an effective
measuring period. Otherwise occuring measuring errors and averaging of the values due to fluctuations in
the radiation source are eliminated. The measured values are obtained with a higher reliability.
The present invention thus enables the measurement of radiation from an electromagnetic radiation
source so as to achieve a high precision of measurement, a short measuring time and the substantial
elimination of ambient influences.
In order that the invention may be more readily understood, reference is made to the accompanying
drawings which illustrate diagrammatically and by way of example four embodiments thereof and where:
Figure 1 is a schematic view of a radiation energy measuring arrangement;
Figure 2 is a schematic enlarged view of a portion of Figure 1, showing a thermo-electric sensing member,
Figure 3 is an exploded schematic view of a sensing member in a difference measuring arrangement for
detecting radiation energy,
Figure 4 is a schematic view of an evaluation unit for the arrangements of Figures 1 to 3,
Figure 5 is a schematic view of an arrangement for determining the radiation energy and the radiation divergence, and
Figure 6 is a schematic view of a further embodiment for determining the radiation energy and divergence.
In Figure 1 an arrangement for measuring a radiation energy 9 emitted by an electro-magnetic radiation source (not shown) and operating on the calorimetric principle comprises a circular base 30 provided with a centrally arranged disc-shaped absorbing member 1 which carries a circular groove pattern 31. The absorbing member 1 is surrounded by a first annular arrangement 5 of thermo-electric members 2. The internal annular arrangement 5 of thermo-electric members 2 is, in turn, surrounded at a spaced relation by an external annular arrangement 4 of thermo-electric members 2'.
The individual members 2 and 2' of external annular arrangement 4 and the internal annular arrangement 5, respectively, are both of laminar structure, the opposing members 2' and 2 being connected to each other via thermo-resistance bridges 6.
For the sake of simplicitiy only a few laminas (thermo-electric members 2, 2') are shown.
The adjacently arranged laminas 2 and 2' are electrically and thermally insulated from neighbouring ones by small strips 32 and 32' respectively.
The laminas 2' of the external annular arrangement 4 are thermally connected to a thermal reservoir substantially identical in shape to said arrangement 4 and in close contact to the latter but, however, electrically insulated by respective means (not shown), for example, a varnish layer. The laminas 2' of the external annular arrangement 4 are electrically connected to the laminas 2 which are adjacent the respective opposing ones, whereby a series connection is established via lines 7 between the external and the internal annular arrangements 4 and 5. The internal and external annular arrangements 4, 5 are provided with terminals 8' for lines 8" which connect the arrangements 4 and 5 to an evaluation unit 8.
In Figure 2 a portion of Figure 1 is shown. The absorbing member 1 is thermally contacting the laminas 2 (thermo-electric members 2) which are connected via thermal resistance bridges 6 to the laminas 2' (thermo-electric members 2') which are covered by a thermal reservoir 3, the laminas 2' therefore being shown in dashed lines. The geometry of the thermal reservoir 3 is different to that of Figure 1, but it can also be of circular shape. The thermal reservoir 3 is made of a thermally good-conducting material, such as copper, the thermal capacity of which is a multiple of that of the thermo-electric members 2'. The base 30 is of electrically insulating material, but thermally conductive. It renders the entire arrangement sufficiently stable.
The base 30 is sandwiched between the thermal reservoir3 on the one hand, and the absorbing member 1, the external and internal annular arrangements 4, 5, on the other hand.
In operation, the radiation beam 9 emitted from the radiation source (not shown) impinges upon the absorbing member 1 provided with a 60 groove pattern 31 on its surface in order to increase the efficiency of said member 1. The disc material is selected from blackened metals. Alternatively graphite can be used. It is also feasible to use conical elements instead of the disc-shaped absorbing members 1 (Figure 4).
The radiation beam 9 effects a temperature increase in the absorbing member 1 and, in the course of the resulting thermal flow from the contacting lamina 2 via the thermal resistance bridge 6 and the lamina 2' to the thermal reservoir 3, a thermal difference results which produces a thermo-voltage. The latter is measured by the evaluation member 8 via the terminals 8' and the connection lines 8".
The annular arrangements in Figure 1 permit electrical integration of the differential amounts of heat produced at different portions of the absorbing member 1 independent of the location of impingement of the beam 9 on said absorbing member 1 and of the intensity distribution across the radiation cross-section.
It is feasible to embody the arrangement of Figure 1 as a printed circuit on an insulating base material similar to base 30. The thermo-electric members constituted of the lamina 2, 2' and the heat resistance 6 can be, for example, produced by etching and the electrical connections are produced in a simultaneous step.
It is further feasible to insert the thermal-resistance bridges 6 as resistance wires into the etched circuit structure in thermal and electric connection with the laminas 2, 2'.
Thus an increase of the thermo-electric effect is obtained. Also a combination of both solutions in which the heat resistance bridges 6 are embodied as etched circuitry and/or by a resistance wire is feasible.
The above embodiment of the thermo-electric members 2, 2' permits a simple production of a greater number of sensing members for radiation measuring arrangements with relatively low technological expenditure.
Since the width of the etched circuit paths can be dimensioned precisely, and due to the favourable thermal insulation and to the low irradiation, the thermo-electric members are easily reproducible, and so are the measuring results.
The decay time can be determined by the width of the etched circuit paths, and a measurement of pulsed radiations is feasible.
In Figure 3 an exploded view of a differential sensing member is shown which operates on the differential measuring principle. On a common base 32 two sensing members 33, 34 similar to that of Figure 1 are arranged one above the other. The absorbing members are shown in spaced relation to the sensing members 33, 34 and are constituted by a measuring absorbing member 35 and a reference absorbing member 36 again in spaced relation to the heat reservoir 3 which is provided with holes 33', 34'.
This embodiment also can be realised on a printed circuit panel. In a similar manner to Figure 1 an external arrangement 37 and 38, respectively, of laminas and the internal lamina arrangement 37' and 38', respectively, of laminas are located on annular paths, variations in combination with the absorbing member 1 being, however, feasible.
Also the number of individual laminas is variable, depending on the required measuring precision. The number of the external and internal laminas should be equal.
The absorbing member 35,36 in Figure 3 can be provided with a heater resistance (Figure 4), such as a sheet resistance or a heater winding, which permits an easy absolute calibration of the sensing member by introducing a known energy amount. Thus a quick readiness for measurement is achieved.
The reference absorbing member 36 is brought to the same temperature as the absorbing member 35 after measurement by addition of a definite amount of energy.
The time required is double the decay time, and, hence, is two times lower than the otherwise occuring decay time constant.
Furthermore, a zero-drift is eliminated during a measurement or between two measurements.
This embodiment is advantageous for eliminating ambient interferences.
Figure 4 shows a block-scheme of the evaluation member 8 for differential measurement arrangement of
Figure 3.
An amplifier 10 is connected via its input to the output of the sensing member 33. The output of the amplifier 10 is connected to an A/D converter 11 which is connected to a gate 12 and to a switchable voltage source 15, which, in turn, is connected to a heater resistance 17' of the reference absorbing member 36.
A clock-pulse generator 13 is connected to a further input of the gate 12 which, in turn is connected to a counter 14. A heater resistance 17 of the measuring absorbing member 35 is connected to a calibration generator 16.
The absorbing member 35,36 are cone-shaped. The heater resistance 17 serves to calibrate the sensing member 33.
The A/D converter 11 is a voltage-time converter and controls the On-state of the gate for the counter 14 which, at the same time, switches the voltage source 15, for this On-period. The latter feeds a current pulse via the heater resistance 17' into the reference absorbing member 36 which receives the same amount of energy as the measuring absorbing member 35 has received from the radiation 9.
An absolute calibration of the sensing member is performed by the calibration generator 16 via the calibration heater resistance 17.
The sensing members disclosed hereinbefore permit a precise and rapid measurement of the entire radiation energy of an electro-magnetic radiation source.
In Figure 5 an arrangement is shown for measuring the entire energy distributed over the cross-section of a radiation beam emitted from a radiation source 18, that is the radiation divergence remote from the radiation source 18.
The latter emits a beam 19 which impinges upon a first sensing member 22 comprising an absorbing member 39, the other members being omitted for the sake of simplicity but, however, are similar to those disclosed in connection with Figures 1 and 2. The absorbing member 39 is provided with a central bore 20 for passage of a portion 19' of the light beam 19, whereby the portion 19' impinges upon a sensing member 22' having an absorbing member 39'.
The illustrations of the absorbing members 39 and 39' are sectional views takens parallel to the plane of the drawing.
Only two sensing members 22,22' are arranged for detecting the entire radiation energy and determining the radiation divergence.
It is also feasible to employ a greater number of sensing members similarly constructed to the member 22 and arranged in the beam 19 upstream of the member 22'. The size of the central bore 20 depends on the space angle in which the energy distribution has to be detected. The absorbing member 39' of the sensing member 22' serves to detect the energy of the beam portion 19' which passes unaffected through the central bore(s) 22 of the preceding sensing member 22.
A central evaluation unit 21 is connected via lines 8' and 8", respectively, to the sensing members 22 and 22'. The sensing member 22 measures the radiation energy outside a selected space angle. In contrast thereto, the sensing member 22' detects the radiation energy contained in the beam portion 19' within a selected space angle. A summation of both energy quantities detected by the members 22 and 22' yields the entire energy of the emitted radiation in a simple manner.
Atypical value is 0, which represents the radiation divergence and which is determined by a quotient formation in the central evaluation unit 21 or by any other suitable means, for example, a pocket calculator, in accordance with the following formula: E22 - E22 E22 + E22 where E22 is the radiation energy measured by the sensing member 22, E22 is the radiation energy measured by the sensing member 22', and 8 is the radiation divergence measure.
It is obvious that 0 = 1 indicates a low radiation divergence, whereas results decreasingly > 1 are indicative of an increasing divergence.
In Figure 6 a modification of Figure 5 is shown which permits energy distribution under different space angles. Three sensing members 22,22' and 22" are arranged in a beam portion 19, 19" and 19', respectively, of an electro-magnetic radiation beam emitted by the radiation source 18.
The radiation impinges upon the first absorbing member 39 having a central bore 20 which permits passage of a portion 19" of the beam 19 to impinge upon an absorbing member 39" having a central bore 20' which is of smaller diameter than the bore 20 so that again a portion 19' of the preceding portion is transmitted to the absorbing member 39'. In a similar manner to Figure 5 the absorbing members 39, 39", 39' are connected to an evaluation unit 21 via lines 8', 8"' and 8", respectively.
The arrangement according to Figure 6 permits the detection of the intensity distribution across the entire cross-section of the beam 19, due to the fact that the intensity curve for most radiation sources is known so that only a few measuring points will satisfy.
Using the formula for 0, the exact values for the radiation divergence for each individual space angle can be computed.
It is also feasible to employ more than three sensing members which permits a further subdivision of the space angle intervals.
It is also feasible to operate the arrangement according to Figures 5 and 6 in a different arrangement as described in connection with Figure 3 which requires that the same reference absorbing members 36 are provided with the same central bore 20, 20' etc. as the associated measuring absorbing members 35 in order to increase the measuring precision.
Claims (9)
1. An arrangement operating on the calorimetric principle for measuring the radiation energy of electro-magnetic radiation sources, the arrangement including sensing elements comprising an absorber element, a plurality of thermo-electric elements and a thermal reservoir, wherein said plurality of thermo-electric elements is arranged in a substantially annular external and internal arrangement, both of which are electrically and thermally conducting, and the individual thermo-electric elements are electrically insulated from adjacent ones and are in the form of laminas which are provided with connection lines to connect the internal laminas to the external laminas via thermal resistance bridges, the individual laminas being series connected to integrate the thermal quantities flowing through the individual laminas, and wherein the absorber element is enclosed by said internal annular arrangement and is thermally connected to each individual lamina of said internal annular arrangement, the external annular arrangement being thermally connected to and electrically insulated from the thermal reservoir, and wherein an evaluation unit is electrically connected both to the external and to the internal arrangement of thermo-electric elements.
2. An arrangement as claimed in claim 1, wherein said external substantially annular arrangement and said internal substantially annular arrangement have an equal number of laminas.
3. An arrangement as claimed in claim 1, wherein the internal and the external laminas and the thermal resistor bridges connecting the former to the latter are printed as circuit paths on a base material selected from thermal and electric insulating material.
4. An arrangement as claimed in claim 1, wherein the heat reservoir is made of any suitable thermally conducting material, the thermal capacity of which is a multiple of the thermal capacity of the thermo-electric elements.
5. An arrangement as claimed in claim 1, wherein the thermal-resistor bridges are resistance wires having electrical and thermal connections to the individual laminas.
6. An arrangement as claimed in claim 1, wherein at least two sensing elements are arranged sequentially in an electro-magnetic radiation beam emitted from the radiation source, the absorbing element which is arranged between said radiation source and the other absorbing element of said two sensing elements being provided with a central aperture corresponding to a definite selectable space angle considered in the direction of beam propagation.
7. An arrangement as claimed in claim 6, wherein at least three sensing members are employed in series in the path of beams emitted by the radiation source, the diameters of the apertures in said absorber elements being reduced with increased distance from the radiation source.
8. An arrangement as claimed in claim 7, wherein the sensing members are provided with electrically conductive connections to a central evaluation unit.
9. An arrangement for measuring the radiation energy of electro-magnetic radiation sources, substantially as hereinbefore described with reference to the accompanying drawings.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DD22738881A DD160325A3 (en) | 1981-02-03 | 1981-02-03 | ARRANGEMENT FOR ENERGY MEASUREMENT FOR ELECTROMAGNETIC RADIATION |
DD23224581A DD208496A3 (en) | 1981-07-31 | 1981-07-31 | CALORIMETRIC MEASURING ARRANGEMENT FOR THE RADIATION CHARACTERISTICS OF ELECTROMAGNETIC RADIATION SOURCES |
Publications (1)
Publication Number | Publication Date |
---|---|
GB2095903A true GB2095903A (en) | 1982-10-06 |
Family
ID=25747712
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB8202934A Withdrawn GB2095903A (en) | 1981-02-03 | 1982-02-02 | Thermoelectric arrangement for measuring the radiation energy of an electromagnetic radiation source |
Country Status (3)
Country | Link |
---|---|
GB (1) | GB2095903A (en) |
HU (1) | HU183806B (en) |
YU (1) | YU310381A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE10339952A1 (en) * | 2003-08-29 | 2005-04-07 | Infineon Technologies Ag | Infra red contactless temperature sensor for laser power control has micropeltier elements in integrated construction between insulating substrates |
EP1734350A1 (en) * | 2005-06-13 | 2006-12-20 | LASER POINT s.r.l. | Device for detecting optical parameters of a laser beam. |
-
1981
- 1981-12-28 YU YU03103/81A patent/YU310381A/en unknown
-
1982
- 1982-02-02 HU HU82313A patent/HU183806B/en not_active IP Right Cessation
- 1982-02-02 GB GB8202934A patent/GB2095903A/en not_active Withdrawn
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE10339952A1 (en) * | 2003-08-29 | 2005-04-07 | Infineon Technologies Ag | Infra red contactless temperature sensor for laser power control has micropeltier elements in integrated construction between insulating substrates |
EP1734350A1 (en) * | 2005-06-13 | 2006-12-20 | LASER POINT s.r.l. | Device for detecting optical parameters of a laser beam. |
Also Published As
Publication number | Publication date |
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YU310381A (en) | 1984-08-31 |
HU183806B (en) | 1984-06-28 |
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