Dimensional Verification

Service description

The verification of dimensional and geometrical tolerances is carried out in the metrology laboratory at IFCA and is performed within the scope of the quality system ISO 9001 implemented at IFCA. Two are the equipment¿s used for this service performance, a coordinate measuring machine (CMM) and a vision measuring system. The CMM is a MITUTOYO, model CRYSTA APEX C 574 which measure points in the surface of the part with high precision using contact probe. This points can be linked in order to create geometrical elements like planes, lines, cylinder and measure distance and angles. The measurement range of this equipment is of 600 mm in longitudinal dimension, 500 mm in transverse direction and 400 mm in height. The maximum part weight that can be supported by the CMM table is 180 kg and the maximum part height that can be accommodated is 530 mm. The accuracy of the machine is driven by a formula with a constant part, and a second part dependent of the dimension to be measured. The expression in this case is 2.9+4*L/1000 in microns, where L is the distance being measured in mm. The CMM has two temperature sensors in order to measure verified part temperature in real time, and a thermal expansion compensation system. The probe contact force is between 0.08 N and 0.14N. The CMM machine is installed at the metrology laboratory where the environmental conditions are very stable in dimension and in time and are far lower compared with the maximum values specified by the manufacturer. The mechanical stability is assured by the independent foundation system of the laboratory. With respect to the vision measuring systems, is also a MITUTOYO, model QUICK SCOPE QS200Z. This system allows to measure without contact thanks to a high resolution camera. For the measurement, the part is illuminated with an integrated lamp system and using the camera we are able to measure points where light reflection changes occur. These points can be linked in order to create geometrical elements like planes, cylinders, lines and calculate distances and angles. The measurement range of this equipment is of 180 mm in longitudinal dimension, 180 mm in transverse direction and 85 mm in height. The maximum part weight that can be supported by the table is 10 kg and the maximum part height that can be accommodated is 95 mm. The accuracy of the machine is driven by a formula with a constant part, and a second part dependent of the dimension to be measured. This expression is different for dimensions measured in plane and height measurements. Accuracy expression for the measurement in plane is 2.5+6*L/1000 in microns, where L is the distance being measured in mm. For the case of height, the accuracy expression is 5+6L/1000 microns, where L is the height measurement. This vision measurement system is installed in the clean room at the laboratory of metrology. This clean room is equipped with a temperature and humidity control system, avoiding any effect of environmental parameters in the measurements. The mechanical stability is assured by the independent foundation system of the metrology laboratory. For part series verification, both equipment¿s allow to create specific programs for parts and repeat them automatically, reducing in this way the time needed for the dimensional verification. These specific programs can be edited in order to adapt the program to changes made in part design.