Final answer:
The tolerance zone refers to a range within which measurements are considered acceptable or within tolerance. It is used in quality control to determine whether a product or process meets specified requirements. The tolerance zone is defined by upper and lower limits.
Step-by-step explanation:
In the context of PGL/NSG procedure, the "tolerance zone" refers to a range within which measurements are considered acceptable or within tolerance. It is typically used in the field of quality control to determine whether a product or process meets specified requirements. The tolerance zone is defined by upper and lower limits, often represented as upper tolerance limit (UTL) and lower tolerance limit (LTL), which act as boundaries for acceptable measurements.