A professional who grades samples of asbestos fibers taken from various parts of fiber-manufacturing plant by combining samples and tending machine that agitates known quantity and weight of fibers for specified time.

• Weighs quantity of fibers deposited on each of four screens in machine to find average weight that determines grade of fibers.
• Records grade on bags of fibers according to test results.
• May collect fiber samples from clothing of workers, using portable vacuum device.
• May monitor noise levels at each work station, using sound level meter.