Chain Saws - Problems Associated with Vibration Measurements.
NIOSH 1977 Apr:187-208
The wide variation in chain saw vibration measurements is studied with regard to instrumentation, position of the chain saw relative to the log, hand grasp tightness, different operators and engine speed. An experimental chain saw was used on a square, cross- section, 30 centimeter, knot free Ponderosa pine of low moisture content. Differences as high as 10% in the basic 125 hertz one- third octave band were seen between the Bruel and Kjaer and Spectral Dynamics real time analyzers, and 80%-plus differences were seen in the lower bands. Bruel and Kjaer values were higher in most cases. It was shown statistically that holding the front of the saw against the timber produced significantly greater vibration than holding it away from the timber (not touching). The tightness of the hand grasp was positively correlated with vibration, and the engine speed was inversely correlated. Sizeable differences in vibrations occurred between two different operators. The results emphasize the need for tighter controls of the test procedure and instrumentation when testing chain saws. Experiences of other investigators are related in a discussion.
Measurement-instrumentation; Evaluation; Methodology; Vibration-control; Vibration-meters; Woodcutters; Logging-workers; Lumberjacks; Logging; Lumber-industry-workers; Lumber-industry-equipment; Power-tools;
Proceedings of the International Occupational Hand-Arm Vibration Conference, NIOSH (Paper presented at Cincinnati, Ohio, October 28-31, 1975), Cincinnati, Ohio, DHEW (NIOSH) Publication No. 77-170