Review on 🔦 Accurate Light Meter for 254Nm Lamp Range (220-280) by John Brouillard

This is a short review as I am doing more extensive testing but I wanted to say that this cheap light meter really works. This is not a scam as many of us might think given the relatively low price. Like many others, I was looking for things during the coronavirus that would help keep my family and friends safe. I was interested in UV light disinfection, so I bought two different 25W UV-C Ozone Free lamps. I should have trusted the label and hoped the UV was real, but I really didn't get a chance to test anything other than the banana batter, which actually worked. Most industrial UV-C light meters cost $250-$800 and are calibrated and certified to be precise, but I couldn't justify the cost just to test my lamps. I saw this Santacary UVC Light Meter for 254nm, 220-280nm lamp at Revain for only $120 with no reviews, so I decided to give it a try. A few things: It comes with 2 AAA batteries and a soft carrying case. The display shows the number of microwatts per square centimeter. There is a power switch. Once you press a button, it stays on until you press it again. I mention this because there is another inexpensive UV-C light meter that I will be testing that has a power button that you have to hold down in order to work. In a normally lit room, the counter rose to 10 and stayed there. I think it's normal so I treated it as null. I went outside in direct sunlight (UV-A and UV-B) and the count read 36. I covered the sensor and the count started going down, confirming the sensor is working to detect something. I don't know why the meter detects direct sunlight, but it must mean that this meter detects some UV spectrum present in sunlight, including UV-C. I've also connected the meter to my LED lights, flashlights, and phone lights at home. And they didn't register anything on the light meter. How to place keys, phones, wallets, etc. for disinfection? The ad counter has increased to 1600! With my second UV lamp I tried to place it at the same distance and the meter went up to 1900. This confirmed to me that the meter was indeed detecting UV-C and that my lamps were indeed UV-C. Safety first, so I checked my eye protection gear. I had inexpensive lab glasses that I bought for my kids' birthdays. I turned on the UV lamp and read 1500 on the meter, placed the goggles between the meter sensor and the UV lamp and the number immediately started falling eventually reaching zero. I did the same with my glasses, making sure both the cheap glasses and my glasses were UV blocking. And I wore protective gloves. This is important because UV radiation is harmful to the eyes and skin. I'm not sure I trust the numbers, but the manual says the meter's accuracy is + or - 4%. But for my purposes it's ok. From my research, UV light disinfection is calculated based on the amount of energy absorbed over time. In my test, with 50 mJ/cm² as the energy target, once the counter hits 1600, my calculations show that I only need 30 seconds of exposure. If I want to get to 500 and 1000 mJ/cm2 as an energy target, I need 5.5 and 11 minutes, respectively. I typically use the light for at least 15 minutes each time, so overall the longer you use the light you kill more germs. In addition to microbial growth tests, I will conduct other tests and compare other instruments.