As knows, UV germicidal irradiation is an easy to use pure physical sterilization method. Many homes are equipped with a variety of ultraviolet disinfection equipment, including UV sterilizer cabinet, portable UVC sterilizer wand, etc. But not all UV products are effective because some UV lamps only produce UVA and UVB instead of UVC that can kill germs.

Here, we will share with you two UVC testing methods that are commonly used on the Internet and compare them, to tell you which testing method can help you quickly and effectively determine whether your home UV sterilizer works.

Green Banana Testing

Green banana testing is a simple UV test method and widely spreading on the Internet. Many YouTubers have used this method to detect UV sterilization products on the market, but in fact, it is not a completely accurate detection method.

This method using the phenomenon that the high-power UVC will make the skin of green banana turns brown in a shorter time to detect UV. During the testing, most of the YouTubers irradiate the green bananas with different UV devices, check the degree of brown for the same time, and jungle the UV products that can't turn the green bananas brown within a short time as invalid disinfection device. But in these testing usually overlook the differences in the products' design goals and set powers and make some wrong judgments.

For example, a small public space UV cleaner, the design power may more than 10 W because of using for disinfection larger spaces. While using this device irradiates the green banana, it leads the banana from green turn brown in a short time (maybe tens of minutes). But, if using a LED UVC sterilizer box designed for disinfecting small items such as cellphones to do this testing, the time of green banana turning brown maybe a whole day. Because the UV LED Sterilizer Box's power may be just about 1 to 3W. Although the results of the green banana testing are different, in terms of functional goals of the products themselves, they all can achieve a sterilization rate of 99% within the design time, and they are all the true and effective UVC disinfection products.

Therefore, although the green banana testing can help people detect UVC germicidal products to some extent, it is not so precise.

UV Test Cards

In fact, to test whether a home UV sterilizer can produce UVC, using a UV test card is a far more convenient and effective method than the green banana testing.

UV test cards are made of UV sensitive ink. While UV light irradiates the test card, the area covered with the UV sensitive ink will change color. But before using the UV test card to test UVC, it is necessary to know that there are currently two types of UV test cards on the market, including UV universal test cards and UVC special test cards. Among them, the UV universal test card can only detect whether a light contains UV rays, but it cannot distinguish whether the UV light is UVC. With this type of test card, the test area will turn purple be irradiated by any UV rays, and fade slowly after the UV rays leave. Because it only measures the total light intensity of UV rays, this test card is generally only used to help people prevent sunburn. The other is the UVC special card whose test area is printed with UVC-sensitive fluorescent paint. With this test card, only while the UVC (nor UVA or UVB) is irradiating the test area, the test area will emit fluorescence. And the fluorescence will disappear immediately after the UVC leave.

Therefore, to test the home UV sterilizer, you need to choose a UVC special test card.

Whether the green banana testing or the UV test cards, what they can tell you is only there is UVC in the light or not, but they can't tell you whether the UV device meets your sterilization requirements. If you want to know the sterilization effect, it is recommended to ask the manufacturer for a sterilization test report issued by an authority lab. In addition, even if you use a qualified UV sterilizer, you still need to follow the instructions for operation. If the method of use is inconsistent with the product design, the satisfactory sterilization effect may not be obtained.