Solarmeter Model 4.2 Sensitive UVA Meter, Digital UVA Radiometer, Portable UV Meter for UV Lamp Testing & More, Effective UVA Light Meter, Measures 320-400 nm, from 0-1999 µW/cm² UVA

If you are trying to protect your skin from the sun, this meter is an excellent tool. Made in USA quality.Don't compare this precision instrument to the inexpensive “UV” meters that are available. I have tried several of these, they will often show a reading of 0 or 1 when taken into the shade.Visible light is a small slice of the electromagnetic spectrum. It ranges in wavelength from approximately 400 nm to 700 nm. Red is about 625 - 740, Violet is about 380 - 435.UVA is the closest to visible light. If you will imagine a rainbow with red on one side, and violet on the other side, UVA is an even shorter wavelength than the color violet. UVA (315 to 400 nm), UVB (280 to 315 nm), and UVC (100 to 280 nm). Of the solar UV energy reaching the equator, 95% is UVA and 5% is UVB. No measurable UVC from solar radiation reaches the earth's surface, because the shortest UV wavelengths are completely absorbed by ozone, molecular oxygen, and water vapor in the upper atmosphere.Think you are safe in the shade? Well, you're not. You'd be surprised how much UVA there is in reflected light. When you point this meter directly at the the Sun at around the solar noon, you'll get a reading of about 1500. You step into the shade and the Reading is still around 400. This will depend on the reflective surfaces nearby. Shade IS helpful, but by no means is the UVA anywhere near zero.More recent research is showing that UVA causes the more permanent sun damage. UVB is primarily responsible for sunburn.This meter reads from 0-1999 µW/cm² of UVA.This is an excellent meter for testing window tinting for cars, houses, and commercial buildings. My home is fairly new and has the latest “LOW-E” double pane windows. Nevertheless, even with the windows in the shade I was still getting readings of 6-7. I had 3M 70% window tinting put on some windows where I spend a lot of time, and now the reading is ZERO with the windows in the shade. (70% means 70% of VISIBLE light PASSES THROUGH and 30% is blocked. With 70% window tinting, it's very difficult to tell which windows are tinted and which are not from the inside or the outside of the house.Many people incorrectly believe that the glass in modern cars offers sun protection. Yes, but only partially. Regular glass does a pretty good job of blocking out UVB, but less so with UVA. In my cars, I recorded a variety of readings from side windows. At around noon time, two cars showed 30 to 50. One car showed only about 8. (The wind-shield of a car blocks more UVA than the side windows do, because it is much thicker. This is fortunate, because you cannot tint a windshield, only side windows.)An unknown factor, is the blocking ability of the auto glass alone with no tinting. My cars have always had some kind of tinting on their windows. The car with the lowest reading of UVA was a 2016 Toyota that had dealer installed ‘SolarPlate’. SolarPlate, is made by ‘Permaplate’ and they only sell their product to car dealerships. I telephoned Permaplate 800-453-8470 and was given the names of couple of local car dealers that will install on any car.Before taking any action with my cars, I went to a professional auto-tint installer with many years of experience. They sell some of the best and most expensive auto window tinting. I took samples to the parking lot on a sunny day. They did a good job of blocking UVA when tested by this meter. But NOT AS GOOD as SolarPlate. I took my two other cars to the local Toyota dealer and had my window tinting replaced with SolarPlate. (A great thing about Toyota is unlike some other cars, you can actually shut the lights off.)The two cars that HAD showed 30 to 50 µW/cm² of UVA, now showed 8 to 15 µW/cm² of UVA with SolarPlate. (I have NO financial relationship with SolarPlate, other than being a customer.)You can also use this meter to test clothing and sun-screen. For testing sun-screen, I applied the sunscreen to food wrap.Artificial lighting also emits small amounts of UVA. Florescent, and halogen floodlights gave low readings. Good old fashion tungsten light bulbs and my CREE LED shows zero. With this meter, I was surprised to discover that the lights at the tennis court gave me readings around 10. Even though the lights were about 20 feet above my head.I believe that popular media has misled some people into believing that as long as they stay out of the sun between 10AM and 4PM, you are more or less safe. Inexpensive UV meters will reinforce this belief. You can see ‘UV’ numbers start to drop off dramatically in the late afternoon. I wish it were otherwise, but UVA does not diminish as quickly as UVB.I found the attached diagram on the Internet. You will notice how the blue line (UVB) drops off more quickly than the red line (UVA).You cannot eliminate your exposure to UVA and UVB radiation. But this meter is a powerful tool to help you reduce your exposure to the maximum extent practical. Regarding vitamin D, do your own research. My research shows that a person with a healthy and normal diet will receive enough vitamin D. Besides, despite your best efforts you will still get some vitamin D from the sun.My only very minor criticism of this meter is the battery compartment. It is too small for most lithium 9V batteries. (I NEVER use alkaline 9V batteries.) Besides lasting 4 times longer than alkaline, I have never seen a lithium battery leak. To my knowledge, there is only one lithium 9V battery that matches the size constraints of alkaline, the Ultralife U9VLJPFP. I performed a little trimming inside the case to give the battery compartment a tad more room.Stop guessing about UVA radiation, buy this (Made in USA) meter and you will know what your situation is.

I used this device to check all the bulbs and lights in my residence for the possibility of UVA emission. It also works well for sunlight in a shade which of course does contain UVA. I removed its battery before stowing it away.

Good at sensitive UVA readings. Small, pocket sized and convenient.

Very sensitive when monitoring indoor UVA exposure and too sensitive for exposure to direct sunlight. However works fine outside on a cloudy day.