Published in Forest Products Journal, Volume 28, Issue 1, January 1, 1978, pages 52-57.
NOTE: At the time of publication, the author Douglas D. Piirto was not yet affiliated with Cal Poly.
An evaluation of a pulsed-current resistance meter ("Shigometer®", Model No. 7950) for facilitating detection of decay was performed on wood blocks of giant sequoia heartwood and of white fir sapwood. As decay progressed over a 12-week incubation period, a trend of lower meter readings was obtained, confirming reported field measurements of other workers. Variability in meter readings in situations where the range in resistance readings between sound and decayed wood is narrow (e.g., giant sequoia heartwood) and apparent inability of the meter to make readings necessary to diagnose decay at MCs common to wood in service without ground or water contact are considered to be the major limitations of the instrument. Shortcomings of the instrument, along with suggestions for improvement in meter design, are discussed.