A handheld UV standard source

Abstract

The present invention discloses a handheld ultraviolet standard source, which converts the number of photons detected by different ultraviolet imaging devices to obtain a conversion coefficient. Through this coefficient, the number of photons detected by different ultraviolet imaging devices can be uniformly quantified, so that the photon counting value is no longer limited by the device and the device calculation method, which is convenient for the unified quantitative comparison of ultraviolet detection results and promotes the standardization of ultraviolet inspection work. On the other hand, the ultraviolet standard source is small in size and light in weight, which is convenient for front-line production personnel to carry out on-site inspection and calibration work.

Description

Technical Field

[0001] The invention relates to the technical field of electrical detection, and in particular to a handheld ultraviolet standard source. Background Art

[0002] Different forms of discharge, such as corona, tip discharge, arc, and flashover, often occur outside high-voltage power equipment. Different light waves, sound waves, and ultraviolet signals are radiated during the discharge process. Ultraviolet detection equipment can be used to receive the ultraviolet signal with a wavelength of 240-280nm generated by it. By analyzing, processing, and detecting the number of photons in it, the discharge location and intensity can be determined.

[0003] At present, domestic ultraviolet detection technology is becoming more and more mature, and the corresponding demand for ultraviolet detection equipment is also gradually increasing. On the one hand, in the domestic power industry, an enterprise often purchases ultraviolet imagers from different manufacturers. Ultraviolet detection equipment from different manufacturers has different photon counting methods, which makes the number of photons obtained by these devices different and cannot be compared, which is not conducive to the implementation of ultraviolet inspection standardization. On the other hand, most of the existing domestic ultraviolet standard sources are based on university optical platforms, with many parts and complex adjustments, and cannot be used for on-site inspection and calibration of ultraviolet detection equipment. Summary of the invention

[0004] The technical problem to be solved by the present invention is to make up for the deficiencies of the prior art and propose a handheld ultraviolet standard source to solve the problem that the number of photons detected by different ultraviolet imaging devices cannot be uniformly quantified, and the problem that the ultraviolet standard source components are complex and difficult to adjust.

[0005] The technical problem of the present invention is solved by the following technical solutions:

[0006] A handheld ultraviolet standard source comprises a battery, a constant current source circuit, a duty cycle adjustment circuit and an ultraviolet LED connected in sequence, as well as an attenuator, an optical power meter, a display counting circuit and a touch screen;

[0007] The constant current source circuit and the duty cycle adjustment circuit linearly and smoothly adjust the light intensity of the ultraviolet LED. After the light intensity of the ultraviolet LED is stable, the optical power meter detects the light intensity of the ultraviolet LED and obtains the theoretical value of the number of photons by conversion. An attenuator is installed on the ultraviolet LED and placed in front of the ultraviolet imager to be tested. The ultraviolet imager to be tested detects and obtains the device value of the number of photons.

[0008] The display counting device calculates the correction coefficient of the ultraviolet imager to be tested according to the theoretical value of the photon number and the device value of the photon number, and the display screen displays the correction coefficient, the theoretical value of the photon number and the device value of the photon number.

[0009] The beneficial effects of the present invention compared with the prior art are:

[0010] The present invention develops a handheld ultraviolet standard source, which converts the number of photons detected by different ultraviolet imaging devices into a conversion coefficient. The coefficient can be used to uniformly quantify the number of photons detected by different ultraviolet imaging devices, so that the photon count value is no longer limited by the device and the device calculation method, which is convenient for the unified quantitative comparison of ultraviolet detection results and promotes the standardization of ultraviolet inspection work. On the other hand, the ultraviolet standard source is small in size and light in weight, which is convenient for front-line production personnel to carry out on-site inspection and calibration work. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The figure is a schematic diagram of a handheld ultraviolet standard source of the present invention. DETAILED DESCRIPTION

[0012] The embodiments of the present invention are described below in conjunction with the accompanying drawings.

[0013] The handheld ultraviolet standard source of the present invention is composed of a light source module, an integrated circuit, a power meter and an auxiliary module. The light source module contains an ultraviolet LED and an attenuator. The integrated circuit contains a constant current source circuit, a control circuit, and a display / calculation circuit. The auxiliary module includes a battery and a touch screen. The power meter is an accessory of the handheld ultraviolet standard source and is used for self-calibration of the light source. The purpose of self-calibration is to eliminate the influence of production batch, service life and on-site temperature and humidity on the number of photons output by the ultraviolet LED, so as to ensure the accuracy of the calibration function of the ultraviolet standard source.

[0014] The ultraviolet LED is small in size and light in weight, with a service life of more than 1000 hours and a light source fluctuation rate of less than 0.1%. The attenuator has a fixed attenuation rate, is connected to the light source, and can be manually disassembled. The constant current source circuit is connected to the battery to generate a constant current to drive the ultraviolet LED. The control circuit is connected to the constant current source circuit, and adjusts the light intensity by outputting current signals with different duty cycles to achieve linear and smooth adjustment of the light intensity. The display / calculation circuit is connected to the touch screen and has parameter input, output, calculation and storage functions.

[0015] The working mode of this standard source is: the light source sends out a signal, which enters the device under test after being attenuated by the attenuator. The device under test tests the standard source and then calibrates the number of photons, as follows:

[0016] (1) Turn on the UV standard source, adjust the light intensity, and wait until the light intensity stabilizes (usually 2-5 minutes). Use the optical power meter probe to detect the current light intensity and input it into the device. The device converts it into the theoretical photon number N. 理论 , this step is calibrated when leaving the factory;

[0017] (2) Remove the optical power meter probe and install the attenuator in front of the light source as a whole. Place the whole in front of the device under test at the same height and fixed distance (such as 10m) and turn on the device under test for testing.

[0018] (3) After the device under test is stable, the device detects the number of photons N of the standard source. 设备 , input system;

[0019] (4) The theoretical photon number N calculated by the system based on the standard source 理论 and the number of photons measured by the device under test N 设备 , calculate and obtain the correction coefficient K of the device under test;

[0020] (5) The correction factor K is multiplied by the photons actually detected by the device under test to obtain the corrected photon number N. 正 .

[0021] It uses a single day-blind ultraviolet LED, which is energy-saving, stable and low-power. The light intensity is adjustable through the constant current control method. It is small in size and light in weight, and the test personnel can operate it with one hand. It has a touch screen, which is easy to operate, can input and output data, and can directly output coefficients.

[0022] Typical day-blind UV light sources include mercury lamps, deuterium lamps, xenon lamps, and deep UV LEDs. Mercury lamps, deuterium lamps, and xenon lamps have high radiation intensity, large size, and severe heat generation, and are usually used in large-scale experiments. UV LED lamps mainly radiate UV light of a certain wavelength, with high light energy utilization, low power consumption, long life, low cost, and are cold light sources with small size and light weight. UV LED lamps can meet the requirements of spectral range, divergence angle, and output power, and at the same time, it is easy to reduce the weight and size of the standard source. After comprehensively considering the advantages and disadvantages of various light sources, the UV LED light source was finally selected.

[0023] The ultraviolet LED uses a single LED light source produced by SVC in Seoul, South Korea, with a wavelength of 275±5nm, a light-emitting angle of 120°, a specification of 3.5mm*3.5mm, and a driving current of 20mA.

[0024] The attenuator consists of an attenuation sheet and a lens cover. The attenuation sheet has a diameter of 25 mm (1 inch) and a thickness of 1-3 mm and is fixed in the lens cover. The lens cover can be connected to the UV LED and can be removed manually.

[0025] The constant current source circuit is a DC-DC conversion module that converts the battery current into a stable 20mA current. A duty cycle adjustable circuit using a dual comparator is used. Considering the properties of UV LEDs and the frame rate of the UV imaging device to be tested (usually 25Hz), the duty cycle adjustment circuit frequency is higher than 50Hz. Set 1%, 5%, 10%, 25%, 50%, 75%, 100%, 7 gears adjustable. The display / calculation circuit is connected to the touch screen, and parameters can be input, calculated, and the current status can be displayed.

[0026] The power meter was customized by Japan's HAMAMATSU (Hamamatsu) company, with a response wavelength of 280nm±10nm and a measurement range greater than the maximum power of the LED.

[0027] The battery is customized by Guangdong Andian Energy Technology Co., Ltd., with a capacity of 5200mAh, a rated power of 57.7Wh, and a weight of about 550g. Considering that front-line personnel need to wear gloves to operate, a resistive screen is selected as the touch screen.

[0028] In terms of appearance design, the overall size of the UV standard source is 160mm*100mm*65mm, and it is a rectangular parallelepiped with arc chamfered edges. The surface of the instrument is made of frosted stainless steel, which is silvery white in color, with a granular feel and good anti-slip performance. There is a protective cover above the touch screen to protect the touch screen, and it is printed with the manufacturer's logo. The protective cover can be removed by pulling it out during normal use. The touch screen is tilted upward by 15° for easy viewing and operation. The UV LED light source is located at the front end of the instrument, and it is surrounded by metal threads for easy installation of the attenuator. The battery box and switch are placed at the rear of the instrument, and the battery box is fixed by 4 M3 screws.

[0029] The handheld ultraviolet standard source of the present invention provides a technical basis for the owner enterprise to uniformly and quantitatively evaluate the performance of ultraviolet imagers. In addition, the owner enterprise can build a calibration platform based on a handheld ultraviolet standard source for regular calibration of purchased ultraviolet imagers. For front-line production personnel, a handheld ultraviolet standard source has strong portability and practicality, filling the gap in on-site calibration of ultraviolet imagers. For ultraviolet detection technology, the ultraviolet standard source helps to uniformly and quantitatively compare ultraviolet detection results and promote the standardization of ultraviolet inspection work.

[0030] The above-mentioned embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A handheld ultraviolet standard source, characterized in that: It includes a battery, a constant current source circuit, a duty cycle adjustment circuit and an ultraviolet LED connected in sequence, as well as an attenuator, an optical power meter, a display counting circuit and a touch screen; The constant current source circuit and the duty cycle adjustment circuit linearly and smoothly adjust the light intensity of the ultraviolet LED. After the light intensity of the ultraviolet LED is stable, the optical power meter detects the light intensity of the ultraviolet LED and obtains the theoretical value of the number of photons by conversion. An attenuator is installed on the ultraviolet LED and placed in front of the ultraviolet imager to be tested. The ultraviolet imager to be tested detects and obtains the device value of the number of photons. The display counting device calculates the correction coefficient of the ultraviolet imager to be tested according to the theoretical value of the photon number and the device value of the photon number, and the display screen displays the correction coefficient, the theoretical value of the photon number and the device value of the photon number; The attenuator consists of an attenuation sheet and a lens cover, the attenuation sheet is fixed in the lens cover, and the lens cover is connected to the ultraviolet LED.

2. The handheld ultraviolet standard source according to claim 1, characterized in that: The UV LED uses a single solar-blind UV LED.

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