A professional who tests fiberglass yarn, fibers, or binder solutions at any stage in manufacturing process to determine if standards are met. Respnsibilities include:

• Weighs samples of fiber and binder solution on balance scales before and after drying in miniature oven and burning in muffle furnace, and computes percentage of binder on fiber and percentage of solids in binder solution, using slide rule or mathematical formula.
• Examines and tests goods returned by customer or at customer's establishment to detect manufacturing defects or damage incurred in transit and records results for use by quality control and production supervisors.