Science: Moisture Gauge

Because damp wheat makes musty flour, because damp wood makes warped boards, grain and lumber dealers asked Canada’s National Bureau of Research for a quick, cheap way of measuring the moisture of their goods. The Bureau instructed Professor Eli Franklin Burton of Toronto University to work on it; he put one Arnold Pitt, his graduate student, at the task. Last week their invention was perfected.

It is an electrical moisture gauge, which puts to practical use the knowledge that the more moisture a thing contains, the easier electricity can flow through it.

Student Pitt measured the conductivity of various samples of grain and lumber. These he then dried in an oven, collecting the vapor in an absorbent material which he weighed before and after the baking. This is the way dealers grade their goods. Thus the researcher obtained figures on moisture content and electrical conductivity. These he correlated into a chart. So much electrical resistance meant so much water.

After that it was easy to design a container, connected with an electric circuit and gauge, in which grain or lumber might rest. Where it took hours by the oven process to grade material, the Burton-Pitt machine takes ten minutes.