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Solar Light, LLC

Solarmeter® Model 6.5 UV Index Meter

The instrumentation used to measure UV index for the U.S. E.P.A./NWS program is directed toward the sky in a global normal (perpendicular to level ground) inclination. Therefore the Solarmeter® Model 6.5 is designed to operate in the same fashion. Solar irradiance measured this way includes direct (reduced by cosine law depending on solar zenith angle) plus diffuse (diffused by the atmosphere).

Proper usage of Solarmeter Ultraviolet Radiometer for Outdoor UV Index Measurement

The instrumentation used to measure UV index for the U.S. E.P.A./NWS program is directed toward the sky in a global normal (perpendicular to level ground) inclination. Therefore the Solarmeter® Model 6.5 is designed to operate in the same fashion. Solar irradiance measured this way includes direct (reduced by cosine law depending on solar zenith angle) plus diffuse (diffused by the atmosphere).


This vertical (global) reading represents an average intensity value your body will experience while being active on a tennis or volleyball court, or lying flat on a blanket on the grass. If however, you are reclined in a lounge chair facing the sun perpendicular to the sun angle, you will experience a higher UV intensity, as represented by pointing the Solarmeter ® directly at the sun. This value will typically exceed the actual UV index number.


Sensor

Silicon Carbide (SiC) Photodiode under UV glass window, hermetically sealed with Eeff (erythemally effective) filter and diffuser cap.


To obtain the UV index instantaneous value, the following instructions will provide the most consistent, accurate results:

  • Stand clear of buildings, trees, etc. to obtain a “full sky” field of view.

  • Hold the meter vertical out in front of your body.

  • Press and hold button on front of meter case. Note reading on LCD. This value represents the instantaneous UV index.

  • The highest UVI values typically occur when the sky is a deep blue color, and sometimes when the sun is between scattered white “puffy” clouds. Take extra precaution under these conditions to reduce sunburn potential.


Note that various cloud and haze conditions reduce the UV index. When partly cloudy, take readings often and average clear with cloudy readings to correlate with actual UV index. Take care in hazy or slightly overcast conditions because although the direct UV reads less than when sky is clear, the diffuse UV can be higher… as seen by pointing the meter in various directions.


Long Term Stability

The graph to the right shows how two different Model 6.5 UV Index meters preformed over a 6-year period 1999-2005… at low to very high UVI values. Linear regression R² is 0.992. This data is courtesy of:

Forrest M. Mims IIIGeronimo Creek Observatorywww.forrestmims.org







TOP REVIEWS

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JeremyTengren

average rating is 5 out of 5

Reviewed in the United States on June 17, 2025

Accurate and Easy to Use

This UV meter works great! It gives quick, clear readings and has been really helpful for monitoring sun exposure during outdoor activities. It’s small, portable, and easy to read—even in bright sunlight. Definitely a handy tool for anyone concerned about UV safety.

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Customer_1986_Q

average rating is 5 out of 5

Reviewed in the United States on May 25, 2025

Valuable, life-changing product for a sun-conscious human

Most reviewers bought this meter for a lizard. Guess what... I wanted it to help better protect MYSELF and my family from UV exposure. There's so much misleading info online about how much UV gets through windows, clothes, clouds, etc. Although this sensor is pricey, it was worth it because I was able to get an accurate UV reading in all kinds of conditions and better understand when extra sun protection is really needed. For example, I found that my existing car and house windows do an excellent job of filtering UV (readings of 0.0-0.1 if the outdoor UV index is 7.0). This means I don't need to worry about applying sunscreen (which irritates my skin) every single day to my arms if I'm just going to be driving or sitting near a window. Your windows may differ... according to the internet, many windows don't do a good job of filtering UVA. I also learned that my existing clothes and sun hats block UV well (some internet sources claim that they don't unless you buy special "UPF" products). I confirmed that one warning is true, some UV gets through clouds, and some gets to me on a sunny day even if I'm sitting in the shadow of my house. I was able to verify that all of my prescription sunglasses as well as the cheaper drugstore sunglasses filtered UV as well as they claimed! However, a pair of "toy shades" that came with a costume let a substantial amount of UV through and should not be used as sunglasses! Overall, this meter was a great purchase for peace of mind, for understanding when UV exposure is significant and needs to be mitigated, and avoiding paranoia when it is not.

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SilverSurfer

average rating is 5 out of 5

Reviewed in the United States on July 14, 2022

Works Well

I have a weather station in my yard with a UV meter. The readings on the weather station match the Solarmeter. I checked multiple times during the day. The Solarmeter has a calibration certificate, so that makes me confident my weather station is accurate. I used this to check sunglasses and clothing that claim to block UV actually work, and they do. It only displays the reading while you hold down the button. When you release the button, the reading is gone. I wish it had a hold function for times when it's not convenient to look at the display while taking a measurement. For instance, I'd like to take a sun measurement, then cover the meter with a shirt, and see if it goes to zero. But I have to keep the button held down, so when I remove the shirt I'm measuring direct sunlight again. It's easy enough to get around that, but a hold function would be nice. It still rates 5 stars.

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Amazon Customer

average rating is 1 out of 5

Reviewed in the United States on March 7, 2021

Skip it

Couldn't get this to register anything other than 0.00. Total waste.

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Bri

average rating is 5 out of 5

Reviewed in the United States on September 26, 2025

Worth It

Bought a few years ago-its saved me more than the product cost in T5HO UVB bulbs. Apparently they last WAY longer than the reccommended replacement period. We had one that went for over 2 years until the bulb burnt out.

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Stuart

average rating is 5 out of 5

Reviewed in the United States on September 9, 2025

UV index anytime, anywhere

Like some other purchasers, I don't own lizards - I bought this tool to measure UV radiation in various locations in different circumstances. With my Irish complexion, I've had many skin cancers and needed a simple device that would give quick, accurate readings. This is what I've found out so far: my car, both front windshield and side windows, provides excellent UV protection; at work in my windowed office, again, excellent protection. I've noticed that even in the shade of a tree or building shadow, there are still UV rays getting through (though greatly reduced versus direct sunlight); also, cloud cover cuts the UV rays quite a bit (although not as much as shade does). If you're curious to know the UV index in real time where you are, then buy this nifty product.

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DaleO

average rating is 5 out of 5

Reviewed in the United States on May 19, 2024

It seems to work ok

I haven't had a chanced to do much with it, but it seems to work fine. I was a little surprised that there was just one button that you had to keep pressing down on to get a reading, and apparently no memory cache to hold the reading. But looking at other solar UV meters, this seems to be the standard, so I suppose there is no reason to single this instrument out. It was made in the USA, which may be of importance to customers who believe in maintaining a North American manufacturing base in these sorts of products.

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Happy buyer

average rating is 5 out of 5

Reviewed in the United States on September 30, 2023

Very happy with item and service

I purchased a solar meter to measure UV radiation. I have melanoma and my doctor told me I must protect myself from sun exposure. I had questions so I called the company before I placed my order. John took my call, he was very helpful and kind and he answered all my questions. I received the meter a few days after placing my order. The solar meter is exactly as described on the Amazon page. I immediately started taking UV radiation readings and identified areas where I can be safe and areas where I must use protective clothing or sunscreen. This meter will be an valuable tool to help me avoid further skin damage and cancer risks.

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hugh moore

average rating is 1 out of 5

Reviewed in the United Kingdom on October 24, 2024

absolute rubbish

Complete waste of money giving the same readings indoors as outdoors ,constantly reading 01.9..is this 1.9 or 0.19 ? no instructions very very poor for the money...avoid

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annemarie Fitzgerald

average rating is 4 out of 5

Reviewed in the United Kingdom on February 18, 2019

Very helpful and informative.

Very easy to use and arrived in immaculate condition. My only concern was the calibration of it hadn’t been kept up to date. The calibration date expired in May 2018. I wasn’t aware that this had to be done on an annual basis before.

average rating is 4.4 out of 5

4.4 out of 5

100 global ratings

5 star

82%

4 star

5%

3 star

2%

2 star

0%

1 star

11%

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