An ultraviolet irradiance meter low-value calibration device and calibration method

Abstract

The present application relates to a low-value calibration device and a calibration method for an ultraviolet irradiance meter. The device includes an optical platform, three sets of basic calibration units located on the optical platform, and a standard ultraviolet irradiance meter; each set of basic calibration units includes an ultraviolet light source, a precision aperture, a blind plate, a filter set, and an attenuation plate set arranged in sequence on the same straight line; the ultraviolet light sources of the three sets of basic calibration units are respectively a first ultraviolet light source located in the middle position, a second ultraviolet light source located at the rear, and a third ultraviolet light source located in the front; the light emitted by the three incoherent ultraviolet light sources converges at the center of the receiver of the standard ultraviolet irradiance meter after passing through the precision aperture, the filter set, and the attenuation plate set, and the ultraviolet irradiance meter to be calibrated is placed behind the attenuation plate set in the middle position, and the ultraviolet irradiance meter to be calibrated and the center of the attenuation plate set are on the same horizontal line. The calibration equipment of the present application is few, there is no equipment such as an optical rail, the operation is simple, the cost is low, the device has a small volume, and it can be carried for on-site measurement.

Description

Technical Field

[0001] The present invention relates to the field of optoelectronic technologies, and in particular to a low-value calibration device and a calibration method for an ultraviolet irradiance meter. Background Art

[0002] Ultraviolet detection technology is another optoelectronic detection technology that is dual-use for both military and civilian purposes after infrared and laser detection technologies. Highly sensitive ultraviolet detectors are also widely used in many fields such as flame sensing, ozone detection, laser detection, fluorescence analysis, and astronomical research. An ultraviolet irradiance meter is an important instrument for detecting the radiation intensity of an ultraviolet light source, and is widely used in fields such as ultraviolet detection, medical treatment, epidemic prevention, energy conservation and environmental protection, and optoelectronic reaction.

[0003] The internationally common calibration technology for the ultraviolet band uses a cryogenic radiometer as an absolute standard detector, and trap detectors and thermoelectric detectors as transfer standard detectors to transfer the standard in the ultraviolet band to the silicon detector to be measured. After years of in-depth research, the National Institute of Metrology, China has constructed a set of high-precision ultraviolet radiometers with the NIST ultraviolet standard detector as the core. Performance tests are carried out on each component in the device, and the stability of the entire device is evaluated. On this basis, the self-responsivity standard of the high-precision ultraviolet radiometer is derived. Thus, the first domestic ultraviolet radiometer with high precision, high stability and self-responsivity standard is developed. Major domestic optical metrology stations: Jiangsu Academy of Metrology Science, Zhongce Testing Technology Co., Ltd. of the National Institute of Testing Technology, the First-level Optical Metrology Station for National Defense Science, Technology and Industry (Optical Calibration and Detection Laboratory of Xi'an Institute of Applied Optics), etc. all use the high-precision ultraviolet radiometers developed by the National Institute of Metrology, China to establish ultraviolet radiometer calibration devices, and carry out the work of quantity value transfer according to the "Verification Regulation of Ultraviolet Radiation Illuminance Meters JJG879-2015" by using the comparison method of standard ultraviolet irradiance meters. Since the high-precision ultraviolet radiometers developed by the National Institute of Metrology, China are mainly aimed at ultraviolet radiation illuminance meters used in fields such as nondestructive testing, lithography, disinfection, and curing, and the radiation power is greater than 10 μW. It cannot meet the traceability requirements of low-value irradiance meters. At the same time, since ultraviolet radiation in the range of 100 nm to 200 nm is strongly absorbed in the air, the calibration method specified in the "Verification Regulation of Ultraviolet Radiation Illuminance Meters JJG879-2015" is not applicable to ultraviolet radiation in the range of 100 nm to 200 nm, resulting in the inability to trace ultraviolet radiation in the range of 100 nm to 200 nm.

[0004] Therefore, it is very necessary to develop a low-value calibration device for an ultraviolet irradiance meter, and this device also has important application prospects. Summary of the Invention

[0005] In view of the above problems, the present invention is proposed to provide a low-value calibration device and a calibration method for an ultraviolet irradiance meter that overcome the above problems or at least partially solve the above problems.

[0006] In a first aspect, an ultraviolet irradiance meter low-value calibration device is provided, which includes an optical platform, three sets of calibration basic units located on the optical platform, and a standard ultraviolet irradiance meter; each set of calibration basic units includes an ultraviolet light source, a precision aperture, a blind plate, a filter set, and an attenuation sheet set arranged in sequence on the same straight line; the ultraviolet light sources of the three sets of calibration basic units are respectively a first ultraviolet light source located in the middle position, a second ultraviolet light source located at the rear, and a third ultraviolet light source located at the front; the light emitted by the three incoherent ultraviolet light sources converges at the center of the receiver of the standard ultraviolet irradiance meter after passing through the precision aperture, the filter set, and the attenuation sheet set, and the ultraviolet irradiance meter to be calibrated is placed behind the attenuation sheet set in the middle position, and the center of the ultraviolet irradiance meter to be calibrated and the center of the attenuation sheet set are on the same horizontal line.

[0007] Preferably, the precision aperture is a first-level precision aperture with precise scales.

[0008] Preferably, the outer shell of the ultraviolet light source is designed as a small dark box.

[0009] Preferably, the filter set is a narrow-band filter.

[0010] Preferably, the angle between the line connecting the center of the detection surface of the ultraviolet irradiance meter to be calibrated and the center of the small-hole imaging light source and the optical axis of the ultraviolet light source is not greater than 15°.

[0011] In a second aspect, a calibration method is provided, which is applied to the low-value calibration device of the ultraviolet irradiance meter as described in the first aspect. The method includes the following steps: Step S1, turn on all ultraviolet light sources, remove the blind plate at the middle position where the first ultraviolet light source is located, remove all the attenuation filter sets, and use a standard irradiance meter to read the standard value Q; Step S2, remove the standard irradiance meter, place the ultraviolet irradiance meter to be calibrated at the same position, and read the displayed value of the ultraviolet irradiance meter to be calibrated as the first measured value Q1; Step S3, place the blind plate at the middle position, respectively remove the blind plates at the front and rear positions where the third ultraviolet light source and the second ultraviolet light source are located, adjust the precision diaphragm and place and replace the attenuation filter sets so that the second measured value Q2 and the third measured value Q3 displayed by the ultraviolet irradiance meter to be calibrated are equal when the blind plates at the front and rear positions where the third ultraviolet light source and the second ultraviolet light source are located are removed respectively, and the fourth displayed value Q4 displayed by the ultraviolet irradiance meter to be calibrated when all the blind plates at the front and rear positions where the third ultraviolet light source and the second ultraviolet light source are located are removed is equal to the first measured value Q1 in Step S2. At this time, the illuminance corresponding to Q2 and Q3 is half of the standard value Q in Step S1; Step S4, place the blind plates at the front and rear positions where the third ultraviolet light source and the second ultraviolet light source are located, remove the blind plate at the middle position where the first ultraviolet light source is located, adjust the precision diaphragm and place and replace the attenuation filter sets so that the fifth measured value Q5 = Q2 = Q3 displayed by the ultraviolet irradiance meter to be calibrated. At this time, the illuminance of the first ultraviolet light source is half of the standard value Q in Step S1; Step S5, repeat Steps S1 - S4 until the lowest calibration point of the ultraviolet irradiance meter.

[0012] Since the calibration equipment adopted by the present invention is relatively few and there is no equipment such as an optical rail, the operation is simple and the cost is low; there is no need to use an optical rail, the device is small in volume and can be carried for on-site measurement; the distance between the device to be calibrated and the standard light source is short and does not change, avoiding the calibration error caused by the attenuation of deep ultraviolet light in the air.

[0013] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the specification. And in order to make the above and other objects, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention are specifically exemplified below. Description of the Drawings

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0015] Figure 1 It is a schematic structural diagram of a low-value calibration device for an ultraviolet irradiance meter provided by an embodiment of the present invention;

[0016] Description of the reference numerals in the drawings:

[0017] 1 - Optical platform, 2 - Ultraviolet light source, 3 - Precision aperture, 4 - Blind plate, 5 - Filter set, 6 - Attenuator set, 7 - Standard ultraviolet irradiance meter

[0018] 21 - First ultraviolet light source, 22 - Second ultraviolet light source, 23 - Third ultraviolet light source. Detailed implementation manners

[0019] Hereinafter, exemplary embodiments of the present disclosure will be described in more detail with reference to the drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art.

[0020] The terms "comprising" and "having" in the description embodiments, claims and drawings of the present invention, and any variations thereof, are intended to cover non - exclusive inclusion. For example, a series of steps or units are included.

[0021] Hereinafter, with reference to the drawings and embodiments, the technical solutions of the present invention will be further described in detail.

[0022] As Figure 1 , an embodiment of the present invention provides a low - value calibration device for an ultraviolet irradiance meter, including an optical platform 1, three sets of basic calibration units located on the optical platform 1, and a standard ultraviolet irradiance meter 7.

[0023] Each set of basic calibration units includes an ultraviolet light source 2, a precision aperture 3, a blind plate 4, a filter set 5, and an attenuator set 6 arranged in sequence on the same straight line;

[0024] The ultraviolet light sources 2 of the three sets of basic calibration units are respectively the first ultraviolet light source 21 located in the middle position, the second ultraviolet light source 22 located at the rear, and the third ultraviolet light source 23 located at the front;

[0025] The ultraviolet light source 2, precision aperture 3, blanking plate 4, filter set 5, and attenuation sheet set 6 are fixed on the optical bench 1 in the order from left to right, ensuring that the centers of the ultraviolet light source 2, precision aperture 3, blanking plate 4, filter set 5, and attenuation sheet set 6 are on the same straight line. Three non-coherent ultraviolet light sources 2 of the same model are arranged in the front, middle, and rear with the shortest distance possible. The light emitted by the three non-coherent ultraviolet light sources 2 of the same model converges at the center of the receiver of the standard ultraviolet irradiance meter 7 after passing through the precision aperture 3, blanking plate 4, filter set 5, and attenuation sheet set 6, arranged in the front, middle, and rear with the shortest distance possible. The ultraviolet irradiance meter to be calibrated is placed behind the attenuation sheet set 6 in the middle position, and the center of the ultraviolet irradiance meter to be calibrated is on the same horizontal line as the center of the attenuation sheet set 6.

[0026] Calibration process:

[0027] Step S1: Turn on all ultraviolet light sources 2, remove the blanking plate 4 at the middle position where the first ultraviolet light source 21 is located, remove all the attenuation sheet sets 6, and use the standard irradiance meter 7 to read the standard value Q.

[0028] Step S2: Remove the standard irradiance meter 7, place the ultraviolet irradiance meter to be calibrated at the same position, and read the displayed value of the ultraviolet irradiance meter to be calibrated as the first measured value Q1.

[0029] Step S3: Place the blanking plate 4 at the middle position, respectively remove the blanking plates 4 at the front and rear positions where the third ultraviolet light source 23 and the second ultraviolet light source 22 are located, adjust the precision aperture 3 and place and replace the attenuation sheet set 6 so that the second measured value Q2 and the third measured value Q3 displayed by the ultraviolet irradiance meter to be calibrated are equal when the blanking plates 4 at the front and rear positions where the third ultraviolet light source 23 and the second ultraviolet light source 22 are located are removed respectively, and the fourth displayed value Q4 displayed by the ultraviolet irradiance meter to be calibrated when all the blanking plates 4 at the front and rear positions where the third ultraviolet light source 23 and the second ultraviolet light source 22 are located are removed is equal to the first measured value Q1 in Step S2. At this time, the illuminance corresponding to Q2 and Q3 is half of the standard value Q in Step S1.

[0030] Step S4: Place the blanking plates 4 at the front and rear positions where the third ultraviolet light source 23 and the second ultraviolet light source 22 are located, remove the blanking plate 4 at the middle position where the first ultraviolet light source 21 is located, adjust the precision aperture 3 and place and replace the attenuation sheet set 6 so that the fifth measured value Q5 = Q2 = Q3 displayed by the ultraviolet irradiance meter to be calibrated. At this time, the illuminance of the first ultraviolet light source 21 is half of the standard value Q in Step S1.

[0031] Step S5: Repeat Steps S1 - S4 until the lowest calibration point of the ultraviolet irradiance meter.

[0032] The blind plate 4 plays a role in changing the optical path in the present invention, and is used to realize that two sets of ultraviolet light sources 2 of the same model at the front and rear positions irradiate the ultraviolet irradiance meter to be calibrated simultaneously through the precision diaphragm 3, the filter set 5, and the attenuation sheet set 6, and the optical path replacement that the first ultraviolet light source 21 in the middle position irradiates the ultraviolet irradiance meter to be calibrated alone through the precision diaphragm 3, the filter set 5, and the attenuation sheet set 6.

[0033] In one example, the third ultraviolet light source 23 and the second ultraviolet light source 22 irradiate the ultraviolet irradiance meter to be calibrated simultaneously through the precision diaphragm 3, the filter set 5, and the attenuation sheet set 6 at the front and rear positions where they are located, and the first ultraviolet light source 21 irradiates the ultraviolet irradiance meter to be calibrated alone through the precision diaphragm 3, the filter set 5, and the attenuation sheet set 6 at the middle position where it is located, which is realized by removing and placing the blind plate 4.

[0034] In one example, before calibration, the standard ultraviolet irradiance meter 7 is placed at the same position as the ultraviolet irradiance meter to be calibrated, and the irradiance value generated by the first ultraviolet light source 21 at the middle position alone through the precision diaphragm 3, the filter set 5, and the attenuation sheet set 6 is calibrated as the standard value of the starting calibration point.

[0035] In one example, the precision diaphragm 3 is a first-level precision diaphragm with precise scales, and it needs to be calibrated by a metrology institution according to the scale values regularly.

[0036] In one example, by adjusting the precision diaphragm 3 and replacing the attenuation sheet set 6, the irradiance generated by the first ultraviolet light source 21 at the middle position through the precision diaphragm 3, the filter set 5, and the attenuation sheet set 6 at the middle position during the calibration process is made equal to the sum of the irradiances generated by the third ultraviolet light source 23 and the second ultraviolet light source 22 through the precision diaphragm 3, the filter set 5, and the attenuation sheet set 6 at the front and rear positions where they are located.

[0037] In one example, by adjusting the precision diaphragm 3 and replacing the attenuation sheet set 6, the irradiances generated by the front and rear positions through the precision diaphragm 3, the filter set 5, and the attenuation sheet set 6 are made equal during the calibration process.

[0038] In one example, the measured value of the ultraviolet irradiance meter to be calibrated is attenuated in multiples of 2, 2 2 、2 3 、2 4 ...

[0039] In one example, using an illuminance intensity adjustment system that can record values, the measured value of the ultraviolet irradiance meter to be calibrated can be attenuated in multiples of 1 / 2, 1 / 2 2 、1 / 2 3 、1 / 2 4……Combined attenuation of multiples.

[0040] In one example, the housing of the ultraviolet light source 2 is designed as a small dark box, which can prevent the three ultraviolet light sources 2 from interfering with each other and can shield the interference of stray light, so as to ensure the accuracy and reliability of the traceability value.

[0041] In one example, the filter set 5 is a narrow-band filter. Since some gas ultraviolet light sources 2 have multiple light peak outputs, the spectral characteristics of the filter set 5 are very important. The used filter set 5 should transmit only the selected monochromatic light as much as possible, and the light in other wavelength bands, especially the light in the visible wavelength band, should be completely shielded.

[0042] In one example, the distance between the precision aperture 3 and the attenuation filter set 6 should ensure that the angle between the line connecting the center of the detection surface of the ultraviolet irradiance meter to be calibrated and the center of the small hole imaging light source and the optical axis of the ultraviolet light source is not greater than 15°, so as to achieve that the light intensity non-uniformity of the detection surface of the ultraviolet irradiance meter to be calibrated is lower than 5%.

[0043] Advantages of the present invention:

[0044] (1) Since the starting calibration point is a relatively large ultraviolet radiation irradiance value, the metrological institution can trace back according to

[0045] Verification Regulation of Ultraviolet Radiation Irradiance Meter JJG 879-2002; the precision aperture (3) is a first-class precision aperture with accurate scales, and is regularly calibrated by the metrological institution according to the scales; the standard value of the ultraviolet irradiance is calculated from the standard value of the starting calibration point, the transmittance of the attenuation filter set (6) (calibrated value by the metrological institution) and the light-transmitting aperture of the precision aperture (3) (calibrated value by the metrological institution), so the traceability chain is complete.

[0046] (2) Since the measured value of the ultraviolet irradiance meter to be calibrated is attenuated in multiples of 2, 2 2 2 3 2 4 ……, it can solve the problem that the low-value traceability of the ultraviolet irradiance meter cannot be achieved due to the lack of a low-value standard ultraviolet radiation irradiance meter and a low-value radiation power ultraviolet light source.

[0047] (3) Since in the calibration process from high to low radiation irradiance values, the precision aperture (3) is adjusted and the transmittance of the attenuation filter set (6) and the light-transmitting aperture of the precision aperture (3) are changed, the influencing factors for evaluating the measurement uncertainty of the low-value irradiance of the ultraviolet irradiance meter are not increased compared with those for evaluating the measurement uncertainty of the higher irradiance value of the currently traceability-chain-perfected ultraviolet irradiance meter.

[0048] (4) Since the calibration equipment used is relatively few and there is no equipment such as an optical rail, the operation is simple and the cost is low.

[0049] (5) Since there is no need to use an optical rail, the device is small in size and can be carried for on-site measurement.

[0050] (6) Since the distance between the device under calibration and the standard light source is short and does not change, calibration errors caused by the attenuation of deep ultraviolet light in the air are avoided.

[0051] The above specific implementation manners further elaborate on the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are only specific implementation manners of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A calibration method is applied to a low-value calibration device for an ultraviolet irradiance meter. It is characterized in that it includes: Step S1: Turn on all ultraviolet light sources (2), remove the middle-position blind plate (4) where the first ultraviolet light source (21) is located, remove all attenuation filter sets (6), and use a standard irradiance meter (7) to read the standard value Q. Step S2: Remove the standard irradiance meter (7), place the ultraviolet irradiance meter to be calibrated at the same position, and read the displayed value of the ultraviolet irradiance meter to be calibrated as the first measured value Q1. Step S3: Place the middle-position blind plate (4), respectively remove the front and rear position blind plates (4) where the third ultraviolet light source (23) and the second ultraviolet light source (22) are located, adjust the precision diaphragm (3) and place and replace the attenuation filter sets (6) so that when the front and rear position blind plates (4) where the third ultraviolet light source (23) and the second ultraviolet light source (22) are located are respectively removed, the second measured value Q2 and the third measured value Q3 displayed by the ultraviolet irradiance meter to be calibrated are equal, and when the front and rear position blind plates (4) where the third ultraviolet light source (23) and the second ultraviolet light source (22) are located are all removed, the fourth displayed value Q4 displayed by the ultraviolet irradiance meter to be calibrated is equal to the first measured value Q1 in Step S2. At this time, the illuminance corresponding to Q2 and Q3 is half of the standard value Q in Step S1. Step S4: Place the front and rear position blind plates (4) where the third ultraviolet light source (23) and the second ultraviolet light source (22) are located, remove the middle-position blind plate (4) where the first ultraviolet light source (21) is located, adjust the precision diaphragm (3) and place and replace the attenuation filter sets (6) so that the fifth measured value Q5 displayed by the ultraviolet irradiance meter to be calibrated is Q2 = Q3. At this time, the illuminance of the first ultraviolet light source (21) is half of the standard value Q in Step S1. Step S5: Repeat Steps S1 - S4 until the lowest calibration point of the ultraviolet irradiance meter.

2. A calibration method according to claim 1, It is characterized in that it includes an optical platform (1), three sets of basic calibration units located on the optical platform (1), and a standard ultraviolet irradiance meter (7); Each set of basic calibration units includes an ultraviolet light source (2), a precision diaphragm (3), a blind plate (4), a filter set (5), and an attenuation filter set (6) arranged in sequence on the same straight line; The ultraviolet light sources (2) of the three sets of basic calibration units are respectively the first ultraviolet light source (21) located in the middle position, the second ultraviolet light source (22) located at the rear, and the third ultraviolet light source (23) located at the front; The light emitted by the three incoherent ultraviolet light sources (2) converges at the center of the receiver of the standard ultraviolet irradiance meter (7) after passing through the precision diaphragm (3), the filter set (5), and the attenuation filter set (6). The ultraviolet irradiance meter to be calibrated is placed behind the attenuation filter set (6) in the middle position, and the ultraviolet irradiance meter to be calibrated and the center of the attenuation filter set (6) are on the same horizontal line.

3. A calibration method according to claim 2, It is characterized in that the precision diaphragm (3) is a first-level precision diaphragm with accurate scales.

4. A calibration method according to claim 2, It is characterized in that the outer shell of the ultraviolet light source (2) is designed as a small dark box.

5. A calibration method according to claim 2, characterized in that, the filter set (5) is a narrow-band filter.

6. A calibration method according to claim 2, characterized in that, the angle between the line connecting the center of the detection surface of the ultraviolet irradiance meter to be calibrated and the center of the pinhole imaging light source and the optical axis of the ultraviolet light source is not greater than 15°.

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