The History of Electromagnetic Utility Scanning
How Electromagnetic Induction Became the Scanning Industry Standard
Faraday and Early Electromagnetic Scanning Uses
Electromagnetic technology was discovered by famed British scientist Michael Faraday in 1831, in one of his presentations to the Royal Institute in London. He described not only the process of electromagnetic induction, but hypothesized its use as a measuring device. His paper would lay the groundwork for the invention of the first utility locating tools.
It wasn’t until 1910 that electromagnetic induction started to be used for locating utility lines and faults in pipes or cables. Early technology was cumbersome and required several people to carry and measure the tools, but it provided a basic level of information. The tools were specifically geared to find faults in the utility lines and pipes, which was significant problem at the time.
More portable versions came out over the next decade, attempting to improve both portability and accuracy of the measuring devices. Trained electromagnetic scanners and utility locators became highly sought after, not only by private utility companies, but also by the government and surveying companies who wanted information on buried utility lines. As urban centers and the demand for more power, water and sewer lines grew, so too did the demand for these specialized locators.
American vs European Utility Scanning
Between 1920 and 1940, the demands of urban development placed increased pressure on utility locating services. The urban centers differed widely, however, as US cities became more sprawling and European cities became more condensed.
American electromagnetic locating technology was focused on high frequency, low power and low cost locators that were capable of scanning larger areas, as pipes and utility lines were much further spread out. As these urban areas continued to grow, so did the space the utility lines and grids had to cover, requiring tools that had wider surface area but capable of relatively shallow scanning.
On the other side of the Atlantic, European cities were experiencing growth too, but of a different sort. There, utility lines like cables and pipes were often buried under thick streets, old buildings and years of dirt and debris. These conditions required tools that could scan narrow, but deep trenches of land, and were often more elaborate and difficult to operate. As a result, European utility locators required a much higher level of expertise and education to secure the desired surface scanning data.
Post-War Advances in Utility Scanning
By the 1950s and 60s, technology for commercial applications was booming, and the demand for utility lines and information for urban expansion boomed once again. It was in this time that Dr. Gerhard Fischer developed the Metallascope, the very first high performance buried pipe and utility locating tool, and the precursor to the modern tools we use today. His company is still in existence, producing the M-Scope, a modern version of that originally Metallascope technology.
In the early 1960s, one of the most famous technology companies in history made the next major breakthrough in electromagnetic utility locating. Bell Laboratories, of telephone fame, was struggling to find damage to their newly buried cables. They invented a scanning device with two sensors, which could provide both increased definition as well as provide a rough idea of utility depth. The tool, aptly named the Depthometer, was manufactured in 1964 and became the gold standard for utility locating and subsurface scanning.
The Power of Twin Antenna Scanning
Two antennae scanning devices allowed locating tools to improve both sensitivity and separation, providing a clearer picture and differentiating between different cables and utility lines. It also provided utility locators with automatic depth information, greatly improving the accuracy and usefulness of the tools.
Another significant innovation was the introduction of miniaturized electronic circuitry, heralding a new age of smaller, lighter and more portable equipment for utility locating. Fortunately, this breakthrough came at a time when major renovations on the utility lines and cabling systems in America were underway. Digging up old power, utility and water lines became an everyday occurrence. This increased the need for locating tools that provided pinpoint accuracy, to help minimize damage to roads and other utilities during excavation.
Utility Locating Technology in the Modern Era
Growing demand for utility locating services, and an increasingly complex utility grid with often confusing and overlapping lines, created additional pressure for accuracy and depth in scanning tools. New advances and features began to push the electromagnetic scanning technology further, including:
- Combining active and passive scanning to follow target lines
- Simultaneous Multi-Frequency Scanning to locate multiple lines
- Current detection to test for live utility lines
- Sensitivity measuring along a utility to test for defects
- Push-button depth measuring
- Enhanced multi-surface scanning technology, for concrete, asphalt and water
Today, electromagnetic induction scanning is still the industry standard for non-destructive utility scanning and locating, and is used across the world. Applications range from repairing utility lines, cabling and fiber optics, to mapping out construction sites for safe excavation, to highlighting areas of interest in archaeological digs. GPRS has been on the cutting edge of these technological advances, and continues to train on and utilize the most sophisticated electromagnetic scanning tools for private utility locating. Our team of utility locating contractors and project managers have been used on tens of thousands of job sites across America to help locate, identify and avoid buried utility lines.
From humble beginnings in the 1800’s, to helping give rise to the urban explosion of the 1960s, to serving as a modern instrument for keeping construction sites safe and utility lines intact, the story of electromagnetic induction is an essential part of the American story. GPRS is continuing to write that story today, by providing industry leading utility scanning and locating services to construction and excavation crews across America.