Simple measuring devices have been necessary from the time humans first started making tools.
The first steel tape measure was introduced in 1865, and for decades, electricians have carried compact measuring tapes for numerous tasks on electrical and datacom projects. Laser measuring tools have become a modern alternative, and sonic devices that compute distance using sound waves are another option.
Beyond basic distance measurements, advanced laser equipment simplifies and speeds layout work for commercial and industrial projects.
Laser and sonic devices have appeal and effectively make fast, accurate measurements in many situations, but the trusty tape measure is holding its own in the marketplace.
Traditional measuring tapes are a staple in every electrician’s tool bag, said Bruce Hartranft, product manager of Ideal Industries (www.idealindustries.com).
“This is so because of their durability, simplicity and the comfort level that electricians feel with the manual design, especially when measuring shorter distances in the everyday tasks they’re confronted with, such as positioning conduit hangers or wall boxes. Of course, we also can’t ignore the economics of a manual tape. Overall, they represent a better value than higher priced laser tools,” Hartranft said.
Although available in several lengths, Hartranft said 25-foot models are the most popular with electricians. Features of the latest models make them more versatile and easier to use.
“Ideal lately has made several changes to our standard tape line, mostly based on our outreach to electricians to discover what they would like to see in the design,” Hartranft said. “One excellent example is our new two-sided auto-lock model. Bending electrical conduit for overhead installation can be frustrating. It requires frequent measuring to ensure the correct bend length, a job made all the more difficult by standard tape measures that have graphics on only one side—the wrong side for viewing overhead. Bold black numbers on both sides of the blade eliminate the need to twist the tape by hand to read a measurement. This simple enhancement can take several minutes off a multibend conduit job and provide the contractor with more precise fits.”
Michael Stephens, Greenlee (www.greenlee.com) senior product manager, said that tapes with hooks on the ends allow for more versatile uses and better holding for typical applications.
“For instance, new designs that include double tangs or magnetic tips hold more securely against electrical boxes, and rubber hooks better grip rounded surfaces, like conduit. Recent emphasis on easier-to-read blades seems to have coincided with the aging baby boomer population, with larger graphics and better defined printing. Other improvements include specialty markings, specific to the application, such as stud and joist increment and coloring corresponding to electrical codes,” he said.
Laser distance meters and levels
Laser measuring and/or leveling devices have become must-haves tool for electricians and other trades. Inexpensive models for homeowners are available from various manufacturers at home improvement stores. For professional electricians, manufacturers such as Bosch, Fluke Corp. and Greenlee, have product offerings in the laser category.
Greenlee offers a mini-magnet laser level that projects a bright laser beam for aligning objects, making a variety of applications easier including bending conduit, aligning an electrical panel box or plumbing metal cabinets. The laser target range is just over 240 feet. Three rare-earth magnets hold the tool firmly in place on metal objects.
Bosch (www.boschtools.com) has introduced a digital rangefinder kit and two new laser distance measuring tools to complement two other distance meters.
Fluke Corp. (www.fluke.com) introduced laser distance tools in 2008 and now offers three models that enable quick, accurate distance calculations.
Laser distance meters are used to measure the length of cable and conduit runs to determine material requirements or calculate voltage drops, ceiling height to determine fixture access and calculate light/lumen requirements, distance between machines to estimate heat loading, and room size and duct length, said Brian Sowell, Fluke Corp. manager for service and installation tools.
When the space to be measured is inaccessible—for instance, above a suspended ceiling, behind operating equipment or across a gap—the laser distance meter may be the only safe and practical technology for the job.
“Because they allow fast and accurate measurements and calculations, they help electricians do a better job in less time. Laser distance meters are quickly becoming one of the industry’s standard tools,” Sowell said. “Electricians know they should carry a good digital multimeter. Many now are realizing that they should also have a reliable laser distance meter on their tool belt. No more tape measures and calculators. Electricians are letting the distance meter do the work and calculations.
“In addition, these tools enable quick calculations of distance formulas such as area and volume and make it easy to perform distance addition and subtraction calculations. Higher end models also offer convenience factors, such as a backlit display for working in unlit ceiling spaces and IP54 environmental protection.”
For anyone who has struggled with fractions, today’s laser distance meters can do all the complicated math, he said.
Measuring with sound waves
Another option for measuring distances is a sonic device, which calculates distances by the amount of time an ultrasonic pulse takes to bounce off the target.
Zircon (www.zircon.com), perhaps best known for its electronic stud finders, offers a handheld sonic device that uses a laser beam to target the point of measurement for the cone-shaped sonic beam. The device measures up to distances of 50 feet. Simply point the laser at the target, click the “Read” button, and the distance (in either feet and inches or metrics) appears on the easy-to-read LCD screen. When an accurate measurement cannot be made, an error message is shown, rather than a false reading. The tool stores measurements taken for calculating square footage and volume.
Laser layout systems
Laser layout systems have changed the way electrical projects are laid out.
“It would be unusual for an electrical contractor working in commercial and industrial applications to not use a laser layout or measurement tool,” said Mike Tramontin, executive vice president of Pacific Laser Systems (PLS) (www.plslaser.com), manufacturer of laser layout tools since 1995.
Tramontin said it is important to distinguish the difference between distance measurement and layouts.
“Distance measurement is used to measure distances and to calculate area for materials,” Tramontin said. “Layout lasers are used to determine existing conditions and the layout of critical components such as struts, fixtures and cable. Vertical plumb point-to-point [layout] as well as horizontal layout can be done easily with these products.”
Layout laser systems include point-to-point models, continuous-line lasers, rotating lasers and various accessories such as tripods, mounting brackets and targets.
“We estimate at least 25 percent of any job is devoted to layout of materials,” Tramontin said. “These laser tools will significantly reduce layout time and speed installation. As costs for these tools have declined, more contractors are finding ways to use this technology. Imagine calculating the materials needed for a large plant or commercial building using historic methods like measuring wheels or tapes.”
Trimble Navigation (www.trimble.com) offers a complete laser-based layout system allowing electrical contractors to take designs created in the office to simplify the layout and installation of conduit, pipe, duct and cable trays, said Jarrod Krug, marketing communications manager.
The Trimble system consists of a robotic station, a handheld control device and layout manager software.
“For contractors installing complex electrical systems, the system eliminates conventional tools—such as stationary lasers, string lines and plumb bobs for precise location of duct and cable tray hangers, [and] pipe and electrical conduit sleeves for floor and wall penetrations—throughout the project,” Krug said. “With direct office-to-field functionality, the system enables one person to more accurately lay out hundreds of points in a single day. In fact, one person [can] handle layout faster and more accurately than two people using traditional methods. This efficiency results in both a reduction in labor costs and elimination of mistakes that can result in costly rework.”
The system accepts 2D CAD-based file formats, enabling designers to work with field crews to export their designs (with attachment points) and load them within the layout software. Once in the field, the system takes the 2D design and extends the specific installation needs to the physical field requirements, increasing productivity by reducing rework by facilitating faster, easier and more accurate layout.
As-built point data is collected as points are laid out in the field and can be imported back into office CAD/mechanical--electrical-plumbing software applications for progress reports or to communicate design updates and as-builts.
Wireless capability in the controller enables transfer of design data and daily progress updates between the office and field, reducing delay associated with traveling to and from the job, Krug said.
GRIFFIN, a construction and tools writer from Oklahoma City, can be reached at email@example.com.