Get to Grips with Data Acquisition

Dan Shangraw

In today's increasingly connected world, data acquisition—the art of measuring electrical or physical phenomena such as temperature, pressure, current, voltage, or sound, and then analyzing the resultant data—is important. Without accurate data, you can't design a safer car or airplane; make sure water is safe to drink; build an earthquake-proof building, or ensure that a manufacturing process is working properly. Effective and accurate data acquisition is vital for a variety of scientific and engineering endeavors.

Key to successfully implementing a data acquisition system is an understanding of the variables involved: what kind of sensors exist and how to connect them; what kind of signal conditioning is required for each sensor type; what types of data acquisition hardware exist and how to choose among the offerings available; and how to minimize noise, which can affect the quality of the data you acquire. Noise issues are a common problem for those specifying or using data acquisition systems, so education in the best methods to minimize noise and noise-related errors is important.

Over the last several years, USB data acquisition, in which specialized acquisition hardware connects to a laptop or PC via USB to create a data acquisition system—has become the dominant hardware of choice. At the same time, LabVIEW, National Instruments' graphical data acquisition software, has gained a significant share of the current data acquisition software market. The majority of today's data acquisition applications are now written in LabVIEW. However, in my work I find many engineers and end users are unfamiliar with, or unaware of, USB-based data acquisition hardware. They also lack familiarity with LabVIEW and its capabilities.

At Sensors Expo, on Tuesday, June 7, I will be moderating an all-day symposium on data acquisition systems. Typically data acquisition is not well understood by most engineers. The goal of this seminar is to make attendees—scientists, engineers, or technicians—comfortable with specifying or building their own data acquisition system.

The topics to be covered include how data acquisition affects the measurements you're making; measurement terminology; common sensor types and specifications; signal conditioning for sensor signals; hardware basics; how to minimize noise in data acquisition systems; a discussion of acquisition software, including a brief introduction to LabVIEW; and, finally, an explanation of a sample data acquisition system.

Dan Shangraw, P.E., is the owner and principal of Automated Software Technology (AST) LLC, East Lansing, MI; 517-316-2138. He earned a BS in Mechanical Engineering from Western Michigan University, is a Licensed Professional Engineer in Michigan, and is a Certified LabView Developer. AST is a Certified National Instruments Alliance Partner.