This is a record of the temperature in Randy Bentson's office.

On Thu Mar 11 21:17:24 2004

the initial sensor was placed on my desktop.

On Tue Mar 16 11:41:09 2004

sensors were added to measure the external temp, heat supply temp, and return air temp.

On Thu Jul 1 12:56:10 2004

the outside air temp sensor failed due to corrosion because it was exposed to weather without any shielding.

On Sat May 14 13:12:53 2005

a second system started collecting data. As its configuration is stablized it will be shifted to the Biology Dept's greenhouse to start collecting baseline data. Because the sole sensor is located adjacent to the rear of the system, which is back against a wall, the system's exhaust causes the readings to be slightly higher than the other free-standing sensors in my office. This bias should be reduced when the system is placed in a free standing location.

The temperature sensors are sometimes subjected to heating by direct sunlight--when this happens, the outside temp spikes by 20 degrees Fahrenheit or more.

You may notice that the heating system has a start-up spike, perhaps due to some open-loop component in the control system.

You may also notice some short-term fluctuations in the office temperature during the day. The drop occurs when I open my door and cooler air comes in from the hallway.

Occasionaly noise on the signalling bus has rendered it inoperative. When it does, you'll see a gap in the trace. My wish list includes writing more robust code for the sensors.

Also, on occasion, I shut down the logger while I'm testing new code or system configurations. That'll cause gaps as well.

Following are plots of the last three days, last seven days, and last fourteen days' temperatures. You can click on the image to get a full sized image, and you can use that URL to fetch the image directly in the future.