According to , Metrology “is the science of measurement and includes all theoretical and practical aspects of measurement. Moreover, it is divided into 3 sections: definition of internationally accepted units of measurement, realization of these units of measurement in practice, and application of chains of traceability linking measurements made in practice to reference standards. Metrology Laboratory provides traceability services, both internally and externally. In addition to testing the mass and volume standards for their own inspectors, the metrology program provides testing services for parts, even if it is small.”
A core concept in metrology is metrological traceability, defined by the Joint Committee for Guides in Metrology as “property of a measurement result whereby the result can be related to a reference through a documented unbroken chain of calibrations, each contributing to the measurement uncertainty”. Metrological traceability permits comparison of measurements, so they measure the new result with the old result in the same place (Lab).
The best measurements are the most important to commerce. “About nine out of every ten people working in metrology specialize in commercial measurement, most at the technician level”
The Metrology lab is designed to increase the measurement accuracy and reduce uncertainty. The uncertainty could accrue because of temperature and humidity fluctuations. The lab has amazing machines.
In our tour to HP, I felt the lab has such a great and developed tools and machines which indicates that HP Company does their work precisely. I learned that touching the parts before measuring it will affect the measurements. The parts should be touched by using special material. Plus, there are a machine that sketch the part in a program using software and label all datum. Additionally, it gives most of the dimensions between some parts. This makes some jobs easy and more accurate. Plus, Metrology in HP Campus, do inspections to parts. In the lab, they have the following:
– Calipers (dial, digital, Vernier) measures outside diameters.
– Micrometers (Blade micrometer – reach into narrow slots, etc. Disc micrometer – for flanges and hard to reach areas. Depth micrometer – for holes and slots Screw thread micrometer – measures pitch diameter).
– Dial indicators (Measure machine component alignment and Measure variation of an object).
In the lab, they also check for flatness of an assembly by using granite tooling surface. The steps of that is:
1. Put on surface plate
2. Move dial indicator all over surface
3. Points must all be in the zone
The work area in Metrology lab in HP is well designed. It helps employees to work and increase productivity because in the lab they provide everything is needed. Plus, instructions for new employees if they wanted to use the lab. This helps to reduce human errors. The best part in HP is that they have music in lab. The music was turned on while the man was giving us tour.
The bottom line is that knowing GD&T and gaging is the key to be successful in Metrology labs. The Metrology lab of HP is just an example of how things work. There are many companies use this kind of labs for inspections, for example.