Exactly, this Meter is too broad to accurately measure UVB. You will be getting readings for too large a wavelength. The measurement covers both UVA and UVB, with partial UVC. The reason there are so many models of Solar Meters, is that each one has a very narrow (specific) calibrated wavelength. If you could test this particular meter against known results, you could trend the data for your meter, but without expensive data collection, I wouldn’t risk it. Spend the extra money and use what every zoo/breeding facility has trusted for years. Trust me, I looked for a less expensive tool, couldn’t find one I could trust.