solar radiation.

I wish I could figure out what's going on. I am now running yet a different tube m4011 and I'm still getting crazy high readings during the day. I did some research and found that tube can be somewhat light-sensitive so I wrapped it in a thin sheet of Mylar (came from an alpha radation sensor I dismantled it should let alpha thru) that I cannot see any light through.as soon as the sun came up I started getting readings anywhere from 20 to 168 I'm averaging around 58.according to my specs on this tube it is only a beta and gamma detector so I shouldn't be picking up any Alpha. Attached is an example graph of the difference between day and night my local Sunrise was at 6:14 a.m. you can see in the graph that's when my readings spiked.

It could be noise from your power source. I wonder, do the elevated readings persist if you run the same geiger counter from batteries?

Thanks for the idea. But yes if I run it on batteries it does the same thing. I also have another Geiger counter I only run on batteries and it has elevated readings at the same time this one does.

It still could be a decay product of Radon. See http://www.ccnr.org/radon_chart.html for the decay chain of the most common Radon, and you will see that after it emits it's Alpha particle, the real fun starts. Radon becomes Polonium 218, then Lead 214, Bismuth 214, Polonium 214, and Lead 210. All this in under 1 hour (on average) and producing 2 more Alphas and 2 Betas. Your M4011 detector could be reading these Betas. Try taping a cardboard box down over a detector when the readings are low (thick cardboard stops Alpha and Beta and should keep out Radon gas) and see if there is a difference.

I've set up an experiment to try to determine if radon has anything to do with my high daytime readings. I have my normal sensor that reports to Radmon.org inside of a tupperware container that I have sealed as air tight as possible with tape it's inside a cardboard box that I've sealed with tape in a dark closet inside the house. I have placed my spare sensor outside directly on bare ground placed a tupperware container over it and cover the edges back over with mulch. we'll see what happens. Thank you again to everyone who has given me advice regarding this matter.

Steve

after running the above experiment I am more confused than ever. My indoor sensor sealed double airtight in a dark space still had the exact same elevated readings at the same time (sunrise) I always get them. My outdoor sensor sitting on bare ground covered with a Tupperware container semi sealed to the Earth had the standard readings I would have expected with an average of around 15 to 20 although it did have two or three spikes of over a hundred for a five-second period. I wish or the outside sensor on the ground would have had crazy high readings from radon but it didn't.