The UV energy emitted by [UVLED light sources] is not consistent everywhere. Uv intensity varies with the irradiated distance, in theory, if a [UVLED point source] radiates light uniformly in all directions through a non-absorbent medium, then the irradiance is inversely proportional to the square of the distance.
But in reality, the UVLED is neither a standard point light source, nor is it propagated in a non-absorbent medium, and the traditional UV lamp is not always a single point source, as shown below, the light from the UV lamp hits the radiometer detector from multiple angles, and the reading above the radiometer is not the same as the oblique direction, a phenomenon called cosine deviation. In order to correctly measure the energy of ultraviolet light from different angles, the instrument must correct the Angle between the detector and the UV light source to avoid causing an impact.
Angle cosine correction is achieved by modifying the response of the detector and optical elements such as diffusers. Regardless of the incidence Angle, the detector and diffuser combination has a unit Angle cosine correction. For existing instruments, optical elements are designed to achieve or replicate the cosine response in the instrument. A second complication in the measurement is that these tiny leds do not glow evenly in all directions. The optical properties of current UVLED light sources make it more challenging to decide where to best measure their UV output.
More recently, UVLED lamp manufacturers have begun to develop optical components that can change the output of their arrays again, sometimes with the goal of producing higher irradiance metrics. The optical components developed by different manufacturers are not the same, resulting in inconsistent standards for measuring UVLED irradiance, let alone industry standards. As shown in the figure above, the measurement results can vary greatly depending on the location, even a few millimeters apart. The energy at the semiconductor luminescence can be as high as 70W/cm², which is reduced to 10W/cm² on the surface of the hemispherical lens, and the light outlet window at the illuminating head becomes 8W/cm², and the distance from the light outlet window is 5mm, and the energy is halved. It can be seen that the difference between different measurement positions is large. On the market, energy meters made in the United States are generally used for measurement, and the author thinks it is worth recommending.
What is explained above is the relevant knowledge of the application of precautions when measuring the irradiation energy of UVLED. Auvcure is a professional manufacturer of all kinds of UVLED point light source, [UVLED line light source], UVLED surface light source and [UV curing machine], and can provide solutions and customization according to the actual needs of customers. The company has Japanese production technology, products are exported to South Korea, Japan, the United States, Brazil and other places. Welcome friends from all walks of life exchange guidance. If you want to know more about the UV curing machine, welcome to consult customer service online or call the company’s service hotline for consultation, we will be happy to provide you with quality service! Some of the information/pictures in this article are from the Internet, only for the purpose of sharing new information in the industry, not for commercial use. If any rights are involved, please inform us immediately, and we will delete it immediately. Thank you.
