Collaboration: Monitoring Performance & Building Research

Temperature and moisture sensors for many points in walls, floors and ceilings were installed for ongoing monitoring. This effort is a field research project of the Madison Area Technical College, with generous help from Computer Electronics Program Director Terry O'Laughlin, P.E.

Temperature sensors
Anthony installs temperature sensors before the earthen floor slab is laid down. We're using precision integrated-circuit sensors, LM34 from National Semiconductor, soldered to teflon-sheathed shielded cable, and double-sealed to keep out moisture. We tested the assemblies before and after the installation with a Fluke 8010M multi-meter. These accurate, low-cost sensors have output voltage that is linearly proportional to Fahrenheit temperature, which makes for convenient direct reading.

left: Sequence of fabrication....
The small brass screws are spaced the same distance apart as the probes of our Delmhost BD-10 moisture meter. The wires allow for accurate remote readings of the plugs deep in a wall. After soldering, the connections are thoroughly covered with an insulating coating to prevent a false reading.

Since the meter is calibrated for Douglas Fir, we're able to monitor comparative moisture levels, and gain insight as to how moisture moves through the walls.

This diagram shows sensor locations in the air core floor. Temperature at each location is measured at three depths: within the earthen slab itself, the air moving within the core, and several inches down into the gravel sub-base.