Until recently purchasers of gage or part dimensional certifications were forced to buy services without sufficient information about the uncertainty of the provider’s measurement results. This could cause the customer to receive inaccurate measurement information. Fortunately, the ISO 17025 current specification for dimentional inspection states laboratories must now provide this information to clients. With this uncertainty information, engineering and purchasing should agree on what accuracy is required. Costs for the required accuracy will weed out sources with insufficient values. Competition will be amongst qualified laboratories.
Uncertainty values from job shop laboratories can be larger than the total tolerance of the parts/gages being measured and still be provided to customers as good data. This accuracy mismatch allows bad parts to be accepted and good parts to be rejected. The unfit gage becomes a bandit to the process and steals production.
Hidden costs negate the higher prices for appropriate uncertainty values.
At Bobier Metrology Solutions we have provided uncertainty values on each quote and certificate for over 10 years. Our temperature controlled dimensional laboratory holds 68°F +/- 0.5 degrees with 40% humidity, to lower our uncertainty values. We also perform monthly long term accuracy checks on our equipment.
Comments are closed.