How to Choose & Use UV Light Germicidal Bulbs
There are many types of UV lights developed today, including lamps for tanning and for counterfeit currency detection, black lights for stage performance, as well as lamps for mining. In this article, we are to focus on the UV light germicidal bulbs.
Now, let’s discuss the factors that impact disinfection efficiency and different types of UV germicidal bulbs.
How to Improve the Efficiency of UV Light Germicidal Bulbs?
UV rays can be emitted by mercury vapor low and medium pressure lights. The low-pressure lamps are the most effective as they generate most radiation energy at the wavelength of 253.7nm (the spectrum of UVC light). Low-pressure lamps thus are more widely used in UV germicidal applications.
All UV light germicidal bulbs emit secondary radiation (including small amounts of UVA and UVB lights) and heat. Be careful, when selecting a UV germicidal lamp, the blue glow does not mean that it is effective which is mistaken by most people. The germicidal effectiveness can only be determined using proper UVC sensors and monitors.
Like all gas discharge lamps, when the lamp surface temperature lower or higher than the optimal value, the UV output the UV germicidal lamps is reduced as well. Various types of germicidal lamps offer different levels of performance. The performance of the lamp itself and the cooling of air/water both have a noticeable impact on the disinfection efficiency.
Besides the temperature, the transparency or transmittance of the media also influences the efficiency of UV light germicidal bulbs. The more energy is lost in the absorption process, the less energy is left to kill the microorganism.
For example, if you want to improve the sterilization performance of your UV water purification system, maintaining good transmittance of water matters a lot. And for the air purification application, materials with high UVC reflection property are recommended. These materials can multiply the disinfection effectiveness of your UV lamps.
Tests also have shown that when the humidity of surroundings is high, the germicidal performance of UV bulbs is degraded. You could choose UV germicidal bulbs with excellent water-proof coating. And if used indoors, effectively controlling the humidity is also helpful.
What Type of UV Germicidal Bulbs to Choose
Cold cathode germicidal UV lights
The cold cathode UV lights are instant-start lights with a cylindrical cold cathode type of electrode. Most cold cathode lights use a Vycor quartz tube combined with a rugged electrode structure, making them relatively durable than other types of UV lamps. This type of UV germicidal lamps offer good UV output even at lower temperature and the service life is less affected by the frequent startup. This type of UV light germicidal bulbs is widely used in germicidal applications for its sturdy electrodes.
Hot cathode germicidal UV lights
In operation, the hot cathode UV germicidal bulbs are similar to a fluorescent bulb. They operate with a ballast or transformer and need a device to preheat the electrodes to startups. Their electrodes are tungsten filaments, determining the working life of the lamps. Unlike the cold cathode UV lights, the frequent starts and low temperature actually shorten the life of hot cathode UV bulbs. At low temperatures, to ensure the reliable operation of this type of bulbs, special equipment might be needed.
Slimline germicidal UV lights
The germicidal UV light is an instant-start lamp. Its working life is determined by its electrode life and starting frequency.
With high initial ultraviolet radiation and good maintenance performance, this kind of germicidal light bulbs is especially suitable for the occasions requiring high intensity ultraviolet radiation such as conveyor lines and surface disinfection.
LED UV lights
With the constant development of UV technology, a brand-new kind of germicidal is on the rise - LED UV light. It is expected to eliminate the traditional UV lights out of the competition in the near future. LED UV lights have better characteristics. But due to the limitations of production technology in this respect, Today’s LED UV lamps cannot compete with the high output UV lamps.
High output UV germicidal lights
The high output UV light is the result of the latest UV light manufacturing technology. It renders high UV output in a wide temperature range and consistent UV radiation.
Built with the automatic electronic ballasts, it also ensures the lowest tolerance and maximum UV stability. Its life span is up to12,000 hours.
This type of germicidal bulbs is setting the standards for the development of high-performance UV systems.
Tips about UV Germicidal Bulbs
In general, over the lifespan of 9,000 and 17,000 hours, the output of UV germicidal bulbs decreases by about 15-40%. You could consult the manufacturers for more detailed information about the life expectancy of their UV bulbs.
To ensure the long service life of your UV germicidal lights, you should consider the decrease in UV output in the design phase of your UV germicidal system. The most traditional approach is to choose the UV light germicidal bulbs based on the final UV output at the end of the service life, which can effectively avoid the lamp aging problem.
In addition, you should always keep your UV lamp clean and free of dust. The dust accumulation on the lamp can absorb the UV radiation energy and transfer it to heat, which could lower the effectiveness of the lamps.