Those readings are very much what you'd expect at this time of the year, Susan.
The UVB is determined largely by the altitude of the sun in the sky. In winter when the sun is low in the sky and there is also a lot of moisture in the atmosphere, most of the shorter wavelengths of UVB are absorbed by the atmosphere and never reach us.
That's why you can hardly make any vitamin D in your skin in the winter; possibly none at all in winter above latitude 35 N.
If there is cloud cover you will get very much lower readings, even close to zero. And if you stand close to trees or buildings that shade the sky, likewise these shade out the scattered UVB from the sky so you'll see lower readings.
To see the highest readings possible, aim the meter sensor directly at the sun when it is in a clear patch of blue sky.
You'll be amazed how the daily maximum readings soar as Spring comes and the sun gets higher each day....
Have a look at our own sets of readings, in our Files. A few years back, many members in this Group all went out together on the solstices and equinoxes, and we collected all these readings across the world!
--- In UVB_Meter_Owners@yahoogroups.com, Susan Mule wrote:
> Wait, I went outside again and took another reading, this time pointing the meter directly up at the sky. I got a reading this time of 153. That is still low compared to the chart I am looking at (http://startortoises.net/uvb-readings.html), but the chart was from Spring. The guy I bought the meter from said that he put a new battery in it right before mailing it.
> I bought a used solarmeter 6.2 off of Ebay. It is a bright sunny January day, just outside Houston, TX at 12:50 pm. I am only getting a reading of 055. Is the meter bad or is it just this time of year?