With the TSic 306 installed in the scale I got thinking on how to measure the temperature drift of the load cell. I needed some way to cool and warm the scale just like when it's exposed to weather in the birdhouse. I eventually decided to put the scale into a small cardboard box and from there into the freezer of my refrigerator. There it could cool down over night and in the morning I would take it out and hook it up to the Grasshopper to watch it thaw. While it was thawing the Grasshopper would probe the weight of the empty scale and also record the changing temperature. In the image below you can see the tare point of the load cell change with the temperature:

The image shows three measurement series (1.log, 3.log, 4.log). The Grasshopper did a tare first thing after getting the scale out of the freezer. And after that you can see the tare point sink further and further the warmer the scale gets. The measurement series are almost linear which should make it easy to compensate using the formula below:

After applying this correction the measurement series look like this:

Using this simple formula the temperature drift changed from 4-5g to less than 0.5g over the temperature range measured. Implementing this into the Grasshopper should not be difficult. But it remains to be seen if this will also work in a real world environment.