Accuracy and precision of measuring & test equipment (M&TE) have been topics of previous Currents articles (November and December 2014). A related topic that was not covered in the previous articles is resolution. The Joint Committee for Guides in Metrology document JCGM 200:2012 defines resolution as “the smallest change in a quantity being measured that causes a perceptible change in the corresponding indication.” Simplified, it’s the smallest difference that can be measured by the subject equipment. The accuracy of the M&TE must be greater than (less accurate) or equal to the resolution. That is, the M&TE must be able to indicate the value that is compared to the standard during calibration.

Let's briefly revisit the importance of accuracy and precision.

La precisión y exactitud de los equipos de prueba & medida (M&TE) han sido tratadas en artículos previos de Currents (noviembre y diciembre de 2014). Un tema relacionado que no fue cubierto en dichos artículos es la resolución. Este artículo cubrirá ese tema.

Inspection and testing are two of the most important activities performed by service centers. The service center should be focused on minimizing measurement error such that the measurement values are as close to actual values as needed to properly evaluate the measured item.

Motor repair businesses rely upon the quality of their company’s employees and equipment. Documentation is required more often by customers to satisfy their reliability engineers. Supplying erroneous data, even if it is unintentional, can be very disappointing to a customer.

Instrumentation that is not providing correct information can result in inaccurate diagnosis. This could mean returning a motor that still needs work, or putting unnecessary labor into a customer’s product. Neither of these is desirable and could result in customer dissatisfaction. With more of today’s equipment designed to run at full current and many times into the service factor, the margin for error is drastically reduced.

We all know that seemingly small time savings can significantly improve the bottom line. For a service center with a 12% return on investment (ROI), shaving a few minutes off each job is the equivalent of adding 2 manmonths of billing per productive employee. This paper, from the 2005 EASA Convention, provides many tips for increaseing productivity.