Frequently asked questions about UV light meter selection:
1. How to choose various UV illuminance meters?
Answer: A. First confirm the type of UV light source to be measured. Different types of UV light sources need to be measured with different UV illuminance meters. Mainly the wavelength range and intensity of the ultraviolet light source.
B. Look at the range of the ultraviolet light source. For example, the ultraviolet light in the UVA band can be measured with an ultraviolet illuminance meter in the UVC band. It must be inaccurate. For example, the measurement of ultraviolet germicidal lamps used in hospitals must use ultraviolet radiation illuminometers in the UVC band.
C. Look at the intensity range of the ultraviolet light source. Different ultraviolet radiation illuminometers have different ranges.
2. Do all ultraviolet bands have a bactericidal effect?
Answer: No. Only ultraviolet rays in the UVC band have a bactericidal effect, and the main wavelength of medical ultraviolet germicidal lamps is 253.7nm. If it is an ultraviolet lamp in the UVA band, it has no bactericidal effect at all.
3. What are the qualified standards for medical ultraviolet lamps?
Answer: There are the following national standards for 30W straight tube UV lamps: the UV illuminance meter is placed at a place 1m vertically below the UV lamp tube for measurement, and the irradiation intensity of the UV lamp in use must be greater than 70uW/cm2 to be qualified. Different countries have different testing standards for ultraviolet lamps with different wattages.
4. Why is the UV intensity measured by the UV illuminance meter not up to the standard, but the color can be changed with the UV test paper?
Answer: The discoloration of UV test paper has a lot to do with the distance of placement and the length of irradiation time. As long as the test paper is irradiated by UVC, it will change color. It is only a matter of color depth. Whether the intensity of the UV lamp reaches the standard can only be qualitatively determined, and it is very difficult to confirm quantitatively.
