http://www.loggershop.co.uk/tandd/us...r/prod_66.html

A few weeks ago I purchased from The LoggerShop a TandD Thermo Recorder
TR-72U. This particular model has both temperature and humidity logging
and is then can be plugged into a PC via the USB port utilising the T&D
Recorder for Windows software, which is easy to install and use.

The unit itself isn't designed to be left out to the elements so I
placed inside an enlosure for protection.
http://www.southendweather.net/tr72u.jpg

My reason for purchase was to get more accurate minimum temperatures
during the summer months when I move my Davis WMII to the north wall of
the house, where I record more exceptable daytime maximums.

Here are the comparisons thus far this February, some readings are
missing '-' :

Date Davis TR-72U
Tn Tx Tn Tx
1 3.9 8.4 3.9 - Sunny
2 0.3 6.8 -0.6 7.1 Sunny
3 4.8 7.4 - 3.9 Sunny
4 4.0 9.3 3.4 9.3 Sunny
5 6.9 13.1 - 13.1
6 7.6 10.1 7.0 10.4 Sunny
7 2.2 13.0 - -
8 3.4 11.6 2.5 11.7 Sunny
9 1.4 12.6 0.4 13.2 Sunny
10 -2.1 12.4 -2.6 - Sunny
11 0.2 10.6 -0.8 11.3 Sunny
12 -0.4 11.3 -1.2 12.0 Sunny
13 -1.2 11.6 -2.2 - Sunny
14 4.4 6.1 4.2 6.1
15 4.1 6.2 3.9 7.1
16 0.7 5.1 0.6 6.1 Sunny
17 -5.8 7.6 -6.5 8.5 Sunny
18 -4.8 5.4 -5.7 7.2
19 1.3 6.2 1.3 8.0
20 -0.7 6.8 -1.8 8.0
21 4.4 11.3 3.7 11.4
22 10.2 13.2 9.7 13.2

A couple of comments.
1. In it's current location just below the Davis unit even this time of
year on sunny days it records higher temperatures, probably due to the
sun heating the enclosure etc.
2. When the humidity is high (reads 99%), the minimum temperature
recorded can be way out compared to my Davis.
3. It doesn't realy like temperatures below freezing (The spec. say's
down to -10°C, but the accuracy is not good at this end of the range).
4. Generally, when the min/max temps have been 4°C and above it has
proved to be well within the 0.3°C tolerance specified.

My conclusions are that during the winter months it will not perform to
to accuracy of the Davis, but I suspect as the days get warmer and the
humidity lower it will perform better, which is the time I will be using
it to adjust my night time minimums. I will be keeping a Max/Min
thermometer in the same location for comparison in the summer months,
but if I am away for more than one day I will have to use the TR-72U
more closely. I would generally expect the minimums to be 1 or 2 degrees
lower than the Davis in it's summer home on the north wall of the house.

--
Keith (Southend)
http://www.southendweather.net
e-mail: kreh at southendweather dot net