A professional who tests fiberglass products, such as bonded cord, insulation mats, roving, and staple lengths to determine if products conform to specifications. Respnsibilities include:

• Determines breaking strength of bonded cord by mounting sample on arms of testing machine and moving machine controls that apply force necessary to rupture sample.
• Weighs insulation mat, bonded cord, or roving on balance scales before and after drying and computes percentage of moisture, wax binder, and solids in sample, using slide rule.
• Observes machines in operation to detect worn equipment, irregular roving packages, or dull cutters.
• Examines products for defects, such as dirt, frayed ends, clumps in mats, discolorations, and variation in number of ends.
• Measures staple lengths to verify conformance to standards, using ruler.
• Tests speed of machine spindles, using tachometer.
• Records tests results on quality control records and notifies production supervisors, machine repairer, and workers when machine operation, material, or products vary from standards.
• May perform physical tests to determine yarn porosity, diameter, or denier.