Sensing overload

There is a quiet revolution going on in the sensor market as new technologies create a business case for deploying more monitoring devices in plant locations far and wide.

The need for real-time data and analysis in plant processes is the primary motivation for this shift, say industry experts.

At the forefront of the movement are wireless sensor networks, which according to research firm Frost & Sullivan, are being pushed into myriad new applications, helped by a parade of new enabling technologies.

The company’s recent report on the global wireless sensor market says: “Cloud connectivity and development of newer wireless protocols have strengthened deployment of wireless sensor networks in diverse applications.”

However, while users are comfortable employing wireless devices for less critical functions such as tracking production flow and quality, they remain under utilised for control functions, says Rajender Thusu, measurement and instrumentation industry principal for Frost & Sullivan.

Cloud connectivity and development of newer wireless protocols have strengthened deployment of wireless sensor networks in diverse applications

Reliability and security appear to be key user concerns, he says, with end users hesitant to invest the time and money required to address currently limited bandwidth.

Lack of convergence is another challenge compounded by proprietary wireless network standards.

“Enforcement of common wireless sensor network standards will be critical to ensure free data flow, eliminate data packet losses, and sustain pace of transmission,” says Thusu.

To meet diverse market needs, different approaches have been developed.

“WirelessHART protocol and ISA100 are becoming a common standard across industries,” he says.

“With a converged standard, end users can easily integrate process control and automation sensors with other functions such as asset and human tracking systems.”

Moore Industries is one of the companies to have jumped on the wireless bandwagon.

The company says its THZ WirelessHART Temperature solution can eliminate the problem of getting accurate temperature measurements in remote locations where wiring for power and signal connections are limited.

The device combines its Smart HART Temperature Transmitter with the Bullet WirelessHART Adapter by MACTek into a selfpowered package.

Its lithium batteries last up to four to five years which means that the package can be installed without the need for potentially expensive signal wiring or additional power, the company says, saving on long-term maintenance and repair costs associated with wiring.

Sites that are most likely to benefit from this type of technology include remote pumping station or monitoring locations where access to power is limited.

Wireless sensors are seeing rapid uptake in manufacturing and industrial facilities, says Jesse Bonfeld, vice president of business development at Sherborne Sensors.

This is because manufacturers are keen to tap into the benefits that more capable sensors and instrumentation can provide, without the physical challenges associated with wired installations.

“Most facilities have an existing process and physical layout, where modifications to add additional sensor capabilities could have significant impacts to safety, time and cost – all of which can negatively affect both production and the projected return on investment from the sensor programme,” he says.

“One of the major potential benefits is that often a large number of individual wireless sensors can be monitored using a single display device, or with a wide variety of fixed base stations and hand-held readers that are already available.”

He says that wireless solutions are shown to reduce installation costs and sensor installation times dramatically.

“They also increase safety levels because they can often be configured remotely or prior to installation, and swapped out easily for calibration, cleaning and maintenance,” he says.

Extending the boundaries of sensing technology is another area of innovation for Sherborne Sensors.

The company manufactures and supplies high precision inclinometers, accelerometers, force transducers and load cells, as well as instrumentation and accessories.

Robin Butler, sales and marketing director at Sherborne Sensors says the process of continuous casting in the steel industry is a classic application for an inclinometer.

“You have to keep the process continuous, which means the mould must be the correct angle or you may end up with metal flowing too slowly or quickly,” he says.

“These products are designed to keep molten steel flowing at the right pace.”

Force transducers are used in the paper mill industry to maintain correct roller tension and in the pharmaceutical industry to control compression forces in the manufacture of tablets.

“These force transducers have to withstand many cycles of impact,” says Butler.

Although 50% of the company’s business is in standard products such as these, a further 50% are customised, he adds.

“We try to help them select a standard product where possible and then we look at the possibility of manufacturing a custom product rather than compromising on the solution,” says Butler.

Morgan Advanced Materials is another company that offers a customised approach to sensor technology.

The company specialises in making ultrasonic level sensors for a range of process industry sectors including oil and gas, pharmaceuticals and food and beverage production.

“Our customers are more interested in building something into their system than building a system around a sensor,” says Charles Dowling, product engineer at Morgan Advanced Materials.

The main component used in Morgan’s ultrasonic sensors is piezo ceramic material which the company develops into very specific shapes such as spheres, hemispheres, rings for sonar or more commonly into discs or cylinders.

The hard, dense ceramics can be manufactured in almost any given shape or size.

They are chemically inert, and immune to moisture and other atmospheric conditions.

“For process measurements we are seeing a lot of activity in ultrasonic level sensors because they offer sensitivity and wireless connectivity,” says Dowling.

“Everything is now being managed by one computer system and by using ultrasonic technology, the data is already compatible with their system. They can even have it pinged to their smartphone.”

Honeywell has taken a modular view of the sensor market, with a series of instruments that boast interchangeable parts.

The range currently includes pressure, temperature and level transmitter, says Asheesh Arora, general manager of Smart Instrumentation for Honeywell Process Solutions.

The modular and interchangeable structure of the SmartLine instruments means that parts can be stored and swiftly replaced, with simplified configuration and onsite calibration.

“What we have come up with is not a product, but a platform,” says Arora.

“Customers have so many devices which is fine when the project is coming alive, but when the consultants leave, they often have to maintain all of it by themselves.”

The most recent addition to its platform is the SmartLine level transmitter, which has a choice of a basic alphanumeric display or an advanced graphics display.

The advanced graphics display is capable of showing process data in various graphical formats and communicating messages from the control room.