New wireless-enabled sensor technologies are making access to data from remote and difficult-to-reach locations easier — and further advancing the reach of the Industrial Internet of Things (IIOT) at the same time. In fact, wireless monitoring is the key to the IIOT, believes Steve Attri, global product manager at Emerson Automation Solutions, McKinney, Texas, because pervasive sensing techniques based on wireless transmitters allow a plant to monitor anything, anywhere, at a reasonable cost.
For instance, Emerson has launched wirelessly monitored emergency pressure and vacuum relief vents that can be used on storage tanks, including ones located in tricky-to-access parts of a site.
Advances in wireless sensing technology — especially in the gateways that allow connections to ever more wireless devices and communication with critical transmitters — are driving developments such as this, he notes. Other technical improvements include better power module life, which allows wireless transmitters to operate longer at faster update rates, thereby enabling them to transmit data more often, such as once per second for critical measurements.
“Continuous improvement on mitigating interference and overall network improvements means remote wireless transmitters will be able to be installed anywhere, no matter how far the transmitters are located from a control and monitoring system. This opens up wireless monitoring of wellheads, offshore platforms, pipelines, pumping stations and any other system too difficult and expensive to monitor with wired systems,” he explains.
“Today, a plant can implement a wireless monitoring system for steam traps, pumps, pressure relief devices and other equipment for a fraction of the total wired monitoring solution cost,” he adds.
However, the massive amount of data available to a large wireless installation with hundreds of wireless transmitters must be managed carefully, Attri cautions. “This requires a full software solution, ranging from apps analyzing specific subsystems to larger, plant-wide and worldwide software solutions analyzing plant performance and sharing data over the IIOT with other plants and sites in the company’s network,” he notes.
One of the big recent changes is wireless communication beginning to be adopted for flame and gas detection for both combustible and toxic gas measurement, says Sean McLeskey, Shakopee, Minn.-based product manager for Emerson.
Just a few years ago, wireless communication only was available on a few semi-permanent devices with short battery life and limited sensor performance, he explains. Some customers made conventional fixed gas detectors “wireless” by using adapters — gaining the benefit of wireless communication but with the hassle of a hook up to a conventional power source.
“Now, with products like our forthcoming Rosemount 928 wireless gas monitor, end-users are able to achieve much better performance with true integrated wireless devices,” he notes. In the new monitor, which is in final stages of product development, sensors are hot-swappable and can be replaced in the field, with one hand, without the need for tools (Figure 1). The 928 also has an optional discrete output for triggering local alarms.
“Our customers are going to have more options than they had in the past when they think about what can be accomplished in flame and gas detection. Wireless is a big part of that progression and it is already allowing our customers to protect their people and assets in ways that were impossible even only a few months ago,” McLeskey explains.
Meanwhile, SignalFire Wireless Telemetry, Hudson, Mass., started beta-testing in April at undisclosed customers a patented wireless hatch sensor for remote tank monitoring. Known as Hatch Watchdog, it is designed to prevent dangerous emissions and theft of chemicals from tanks. The sensor remotely monitors the angle of a tank hatch and wirelessly reports the hatch’s status — open/closed/cracked — to a central gateway so operators can immediately respond to any deviations from the closed position (Figure 2).