Sustainability push leads to tangible product innovations

New optical readers convert analog gauges and transducers to wireless, while advanced sensor technologies expand manufacturing energy, environment, and safety capabilities.

By Control Engineering Staff March 18, 2009

Innovation is often more about developing a new use for an existing technology than it is about creating a new technology or product out of whole cloth. Two new innovations—both of which grew out of initiatives to help companies save energy and money—serve as great examples of this fact.
One of these is an array of non-invasive sensing and wireless technologies from Cypress Envirosystems. Some of their products, like the Wireless Gauge Reader, literally snap-on to existing dial gauges

Cypress Envirosystems’ Wireless Gauge Reader.

to capture and transmit the readings wirelessly. How do these gauge readers do it? According to Harry Sim, CEO of Cypress Envirosystems, the readers optically capture an image of the analog gauge reading, convert it to a digital reading (which is viewable on the front face of the Cypress gauge reader) and enable the data to be transmitted wirelessly to a central or mobile application.
In developing this technology, Cypress Envirosystems has not created a new gauge or method of measurement, but a way to extend the capability of an analog gauge without requiring the removal of old gauges, breaking any seals, or running any wires. In addition, the gauge is IP65/NEMA 4 rated for outdoor use, does not require new enterprise software, and has optional OPC or BACnet interface to existing building or plant automation system.
Cypress also offers a Wireless Transducer Reader for remote monitoring of analog transducers or instruments with the following outputs: 4-20mA, 0-5V or 0-10V, RS-232, RS-485, thermocouple or thermistor. Like the Gauge Reader, the Transducer Reader does not require changing out existing transducers, the breaking of pressure seals or running of new wires. With the transducer data in a digital format, data logging, trend analysis, notification, and statistical process control can be performed.
More solidly on the sustainable engineering front—due to its energy saving potential—is Cypress’ Wireless Steam Trap Monitor. Again, like the gauge and transducer readers, no breaking of seals or running new wires is required. The steam trap monitor detects faults and alarms on error to avoid leak losses with failed traps, which—on an 1/8-in orifice pipe—can cost up to $5,000 a year. Considering that most plants have a 15-20% failure rate on the hundreds of steam traps typically installed in the steam distribution system, this adds up to a considerable savings.

Click here for more information on Cypress Envirosystems’ products

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Other new advances worthy of attention are the new sensors coming out of Rockwell Automation’s Advanced Technology Laboratories.
“We have sensor programs that touch on energy, environment, and safety,” says Fred Discenzo, manager diagnostics and sensors, Rockwell Automation. “In biofuels, for example, we can continuously look at their chemistry to help predict what will happen and drive a given production process to a more efficient state.”
As an example of these sensors, Discenzo points out a multi-element sensor used to probe the chemistry of fluids. These multiple sense elements can fit on a single substrate (10 microns in size), and be immersed into a fluid to continuously monitor temperature and conductivity by using a varying AC signal to probe the sense elements. “This is useful in probing polar compounds to detect materials or contaminants that could not otherwise be detected with a DC resistance sensor measurement,” Discenzo says.
Because certain species/chemicals oxidize or reduce at certain electrical potentials, another sensor with three electrodes has been placed on that same substrate mentioned above to detect oxidation potential in the vicinity of the electrodes (using a 2-micron tip spacing). Specific voltages are swept over the substrate to learn what the chemistry of the fluid does in reaction.
Adjacent to those three oxidation-sensing electrodes on the substrate is another sensor (comprised of two electrodes) that measures open circuit potential to give a measure of acidity/pH of the solution. Discenzo notes that this is particularly helpful in controlling the digester for production of biofuels. This same sense element can also be used in solvents to measure uptake of oil, as the sensor provides the total acid number in a non-aqueous fluid.
Another unique sensor development to come out of the Rockwell Automation Advanced Technology Labs is one used to monitor the torque of a rotating machine in real time. In this sensor, a photoelastic material is used that exhibits a change in index of refraction as a function of the strain or how much it has been deformed.
“When we look at this material under a polarized light we see a biofringence,” says Discenzo. To understand biofringence, think of the rainbow pattern you see in a soap bubble. “Using this plastic on the shaft of a rotating machine, we’ll see this pattern develop on a shaft undergoing torsional strain or bending. It will exhibit that soap bubble effect in a way that’s reproducible and computable.”
Rockwell’s labs have transformed this plastic into a torque sensor that can be clamped onto the shaft or used as part of a coupling. “We have a processor that interprets that signal using an artificial neural net and gives us a high accuracy measurement of the amount of angular strain or deformation of that part,” says Discenzo. He also notes that, using this new sensor allows testing to be done for less than $100—as task normally performed by commercial torque sensors that typically costs several thousand dollars.
According to Discenzo, accuracy between the two types of sensors is similar. He says the plastic torque sensor provides high frequency information (tens of kilohertz), whereas with typical commercially available torque sensors, users are limited to 300-500 Hz. “With this much more information, we can see how much energy the system is using or if there’s a worn tooth on a gear,” says Discenzo. “As a result, we can say something about the safety and efficiency of the process and equipment.”
David Greenfield , editorial director
Control Engineering News Desk
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