Vibration syndrome in chipping and grinding workers. Engineering measurements.
Wasserman D; Reynolds D; Doyle T
J Occup Med 1984 Oct; 26(10)(Suppl):773-776
A method was developed for measuring acceleration of pneumatic chipping hammers and horizontal grinders used in shipyards and foundries. Piezoelectric accelerometers were attached to the chipping hammers, one at the chisel end, the other at the rear handle of the tool. Small steel blocks were welded directly to the chisel and positioned at the point where the worker would normally hold the chisel point in place and on the chisel handle. (The chisel is not fixed or restrained in the handle and must be held in place by the worker). Accelerometers were mounted on these blocks and vibration was measured parallel to the axis of the chisel. For grinder measurements, accelerometer blocks were mounted on each grinder handle. Each block consisted of three piezoelectric crystal accelerometers mounted on three perpendicular faces of the steel cube. Experienced chipper and grinder workers operated the tools during these tests and were asked to work in their normal manner. For chipping hammers, accelerations on the handle with the hammer at full throttle ranged from 12.3 gravity (G) to 66G. Acceleration on the chisel was approximately 200G at 0.5 to 0.75 throttle and 2,388G at full throttle. For horizontal grinders, acceleration was measured from 0.74 for a grinder in excellent condition with a coarse radial wheel to 79.07G for a grinder in average condition with a cone type wheel. For vertical grinders, accelerations from 49.82G for a grinder in average condition with a new grinding wheel were measured. The authors conclude that this method of mounting the accelerometer overcomes the previous difficulty of destruction of these instruments. Acceleration of chipping hammers is affected by throttle power and accelerometer position. The condition of the grinder and grinding wheel make the greatest difference in acceleration.
NIOSH-Author; Monitoring-systems; Vibration-monitors; Vibration-disease; Vibration-exposure; Occupations; Workers; Vibration-pickups; Vibration-effects; Occupational-exposure; Occupational-hazards; Vibration-control
Journal of Occupational Medicine