These new kits will be ready for distribution in March and rather than have you return your existing loggers we will provide simple instructions on converting them to the new design. We will send all beta testers an updated kit free of charge that will give you two complete temperature logger systems for the study this spring. We will also offer new kits at the original cost for a limited time to all of those that expressed an interest in this program but were not chosen as beta testers and then the kits and other hardware will be available online via the Monarch Watch Shop.
The first thing you might notice is that we have separated the logger from the radiation shield. There are several advantages to doing this, among them: it reduces surface to surface heat transfer to the temperature logger, it makes it easier to remove/replace logger in the field, and allows for greater versatility in using the logger for other projects (additional temperature loggers will be available with or without the shields).
The radiation shield will be white, rectangular in shape, slightly larger than a business card and made up of a thicker expanded pvc material (we are in the process of negotiating this fabrication).
The larger bracket (corner brace) and its two mounting screws will be galvanized steel and the nuts/bolts will be stainless steel. Using a two-hole bracket will offer greater mounting stability and also allow for better airflow; the galvanized/stainless steel will make the entire unit pretty weatherproof.
As far as assembly is concerned, the bracket will be more or less permanently attached to the shield using a machine screw and lock nut (the type with a nylon insert). The logger will come mounted in a plastic keyfob which will slide onto the machine screw and be held in place with a wingnut.
Scott ("MILW") made the point that tiny parts may be lost in the field - if anyone has other suggestions as to what we could use to keep the keyfob firmly attached to the screw (we can't allow it to spin out from under the shield) please let us know! At least the screw is now stationary so this should make things easier to handle. We will provide the dimensions of all hardware to make any quick replacement only a hardware store away.
Please let us know what you think and if you have other feedback that you haven't left here yet about any aspect of our new temperature monitoring studies please drop us a line or start a new topic here to discuss. Thanks again for your participation!
So I did a little "logger validation." I missioned each of the loggers to record temps at 1 minute intervals and then dropped them both into a glass of water; both in the same glass. I left them there for 10 minutes or so, took them out and dried them, and then retrieved the temperature data. From the data, it appears that it took about 2 minutes in the water to equilibrate with the water temperature before I got a flat temperature reading...this was true for both loggers. What is interesting is that they do not record the same temperature. There is a difference of almost 1.0 degree F (0.9 degrees, to be exact) between the two. In a week or so, I am going to repeat the validation sequence and see if the temperature difference between the two loggers is consistent. Assuming it is, there will need to be a correction factor incorporated into the data analysis to determine if the difference between the two heights is real and by what magnitude.
This potential difference should be taken into consideration before drawing any conclusions about significant temperature differences between the upper and lower thermochron at any given location. 
While there are some minor differences, there are not obvious trends, such as the upper logger reading consistently higher than the lower, etc. Correcting for the fact that my 1.5 meter logger records temps 0.9 degrees higher than the 0.5 meter logger, all of the recorded temperatures of the two loggers for the period from 7 June to 30 June differed by only 0.07 degrees. I'm not sure that difference would prove to be statistically significant.