Thermometer 101 Class

Upon review, it looks like I need to retake the Thermometer 101 course.
Besides calibrating them I need to do a complete review and set up.

Here is what I found.

First of all it would not hurt to insure that the batteries in the Digital Thermo-Hygro were fully charged. As you can see this is a Radio Shack model and Radio Shack changed there name years ago, so that means these are probably 5 years old. They don't consume much power, but I first recharged them.

Then I see that this is a dual sensor model, one sensor for temperature and one for Relative Humidity. I may even be a combined sensor, I did not open it to check, but I do see there is a hole pattern for letting air in or through for the sensor. The way I used this was to hang it from a string inside the Mini Cone Greenhouse, and ended up letting it lie on it back. I suspect that this may have blocked the exchange of air so I did not get the actual new temperature as conditions changed since the new air did not/could not get circulated through past the sensor(s).  Perhaps also, some of the soil may have made some of the buttons sticky or at least clogged the vents a bit.

I brought the thermometer inside and cleaned the vents, charged the battery and studied the built in support bracket. I looks like this was intended to be mounted vertical, usually supported by a stand.

So, my plan now is to use freshly charged batteries and hang the thermometer just above the soil inside the Mini Cone Greenhouse rather than set it flat on the dirt. I had been looking for soil temperature as well as temperature inside the cone, but I probably should use a probe senor for that. I only have a oven meat thermometer of this type so will have to plan a soil temperature test for later.

In the mean time I got some overnight temperature using the other thermometer. Still need to check its calibration but the raw data was as follows:

Minimum temperature inside cone on night of 2011 MAR 22 was  -1 C
Minimum temperature inside cone on night of 2011 MAR 23 was +1 C

Maximum temperature inside cone during day of 2011 MAR 22 was +12 C
Maximum temperature inside cone during day of 2011 MAR 23 was   +7 C

Outside temperatures not recorded but there was frost on ground overnight.