Ten years ago, electronic devices for scanning the location of studs in finished walls were new to most builders. These sensors didn't always work well, but they were a definite improvement over rapping the wall with your knuckles or poking holes with nails. Today, Zircon leads the field of manufacturers in this high-tech market, and has introduced several new scanning features into its tool lineup. Newcomer Stanley offers a smaller line of competing products, while lesser-known products, such as Ver Sales's Wall Wizard, have also found their way into hardware stores and lumberyards. Scanning tools suited for light construction fall into three main classes. Basic stud sensors are designed to detect wood studs behind conventional finished wall surfaces such as
