A fit-for-purpose wireless sensing system provides remote visibility into asset condition and performance, minimizing the need for routine field inspections.
Wireless IIoT sensing and monitoring insights
- Industrial monitoring matters for many critical applications; industrial internet of things (IIoT) monitoring can help.
- Fit-for-purpose wireless sensing systems address challenges in many industrial applications.
- Wireless sensors can integrate with existing implementations and will expand capabilities with other wireless platforms.
Operating a manufacturing facility, data or logistics center and many types of commercial buildings requires a wide variety of measurements. These are needed to provide operators and maintenance personnel with situational awareness, and wireless industrial sensors can help. There can be thousands of measurements required, each with an appropriate level of frequency and detail. Consider two hypothetical process manufacturing examples:
- A continuous exothermic reaction in a vessel that must operate at a critical temperature to stay between inefficiency and potential explosion.
- A 350 hp reciprocating compressor where an elevation in the surface temperature of a valve cover indicates a maintenance problem is developing, capable of causing a shutdown if not corrected.
Both call for a temperature reading, but with different requirements:
- The reactor reading is being used to control input of the reactants in conjunction with an automation host system, so it must be precise with frequent updates.
- The compressor reading is not subject to rapid change, nor is it necessary to have high precision. A value plus or minus a few degrees with updates every 15 minutes reported to the maintenance and reliability team is sufficient for trend monitoring and other purposes.
These call for different approaches. Countless process applications exist with many precision instruments and transmitters, critical for operations. Solutions for the second situation, and many other monitoring applications in industrial and commercial applications, require a different type of sensing system. Many industrial and commercial assets today are either not monitored or are checked only through periodic manual inspections, requiring personnel to be physically onsite, often at the point of measurement. This limited visibility often means issues go undetected until failure, leading to unplanned downtime, higher maintenance costs and unnecessary asset redundancy.
The problems holding these solutions back are often cost and complexity. Returning to the initial example, the temperature transmitter required for the reactor is relatively expensive due to its criticality, calling for very high reliability and precision. The transmitter’s sensor is typically installed in a thermowell, which requires detailed design, along with a process penetration. Using the same approach for monitoring the compressor is overkill, hence the importance of designing more cost-effective sensors designed specifically for monitoring.
Why monitoring matters
Some industrial plants, and even some commercial facilities, perform carefully organized and scheduled manual rounds. During these rounds, technicians evaluate equipment condition at prescribed intervals with specialized equipment, such as vibration analyzers and infrared temperature readers, to look for developing problems. Even when these rounds are performed rigorously, high labor costs are incurred, along with exposure of personnel to hazards in some cases. Furthermore, measurements tend to be inconsistent, and issues can arise between rounds. In the worst case, rounds are performed with far less rigor, or maybe not at all. Fortunately, new sensing solutions provide answers to these and related problems.
Courtesy: Emerson
Monitoring where it counts
Historically, where a plant or facility was heavily dependent on a few critical pieces of equipment, those likely had a range of key diagnostic devices permanently installed. All these monitoring components had to be installed and wired, often at considerable expense, which is why they were added only to the most critical pieces of equipment. There were many other installations that could have benefited from the same treatment, but the costs and complexity were simply too high.
More recently, the picture has changed. Process plants have adopted WirelessHART (FieldComm Group) widely for a variety of purposes, so networking infrastructure is often already in place. Consequently, adding diagnostic sensors using WirelessHART communication provides ways to monitor existing and new equipment at far lower cost since no wiring is necessary. Many such sensors (Figure 1) have been available now for more than 10 years, often using the same basic technology as more complex process transmitters. Companies of all sorts have taken this as an opportunity to extend their monitoring deployments, but cost and complexity can remain limiting factors.
Fit-for-purpose sensing systems address issues
As mentioned, instruments and transmitters for process applications must provide high precision and reliability, with service life measured in decades. In most applications, such transmitters also send supplementary diagnostic data and secondary variables. Often, they must provide data updates every few seconds. This kind of capability is not required for most asset monitoring. Equipment condition is not likely to change suddenly outside of a catastrophic failure, nor is there much use for supplementary data, so little bandwidth is needed.
Returning to the opening example, if the reliability team receives an update on the compressor temperature every 15 or 30 minutes, this will likely be more than sufficient. In many cases, even once or twice per shift is still fully useful. When used with a WirelessHART sensor, long update intervals allow for extended battery life, while reducing the amount of data to process and store. These conditions eliminate the need for a full-featured transmitter, so sensors designed for monitoring can be more cost-effective. When more plant assets are equipped with automated monitoring, tedious and haphazard manual rounds can be eliminated, allowing technicians to concentrate on more useful tasks.
Courtesy: Emerson
An industrial internet of things (IIoT) wireless monitoring platform can provide equipment monitoring sensors:
- Built around IIoT concepts using modular components.
- Designed for easy mounting, and moving to different locations.
- Suited specifically for asset monitoring measurements and data streams.
- With WirelessHART communications protocol.
- Using internal power so no wiring is required.
An IIoT temperature monitor (Figure 2) is designed for taking surface or ambient readings in a variety of applications, with simple mounting using a bracket or magnets for a flat surface, or hose clamps for pipe mounting. A WirelessHART repeater is also available, extending the range and reliability of the network where device counts are too low to provide sufficient wireless mesh network interaction.
Courtesy: Emerson
This device can now be deployed in many applications where equipment temperature is an indicator of condition:
- Motor housings
- Compressor housings
- Bearings
- Gear boxes
- Heat exchangers
- Ambient temperature
- And others.
Wireless temperature monitor information can be integrated with maintenance and reliability platform applications (Figure 3).
Courtesy: Emerson
Integrating wireless sensing with existing implementations
Wireless temperature monitors are designed to work in conjunction with process transmitters and other monitoring sensors. For example, this segment of a carbon dioxide capture unit (Figure 4) illustrates how they can be deployed alongside conventional temperature transmitters to deliver data for strategic equipment monitoring points. The monitors are not tied to the unit’s automation host as they are not intended for process control, they are instead used to monitor the supporting equipment, such as pumps and heat exchanger exteriors.
Wireless monitoring evolution continues
Wireless temperature monitor can use WirelessHART communications. Other options are planned, such as cellular and LoRaWAN (LoRa Alliance). WirelessHART can integrate a large numbers of instruments in close proximity by exchanging large data packages at relatively fast update rates. This is often the case for monitoring sensors as well, however manufacturing assets requiring monitoring can frequently be more spread out geographically with fewer installations over a large space, such as in large logistics center.
In some environments, a different wireless protocol, such as LoRaWAN is better suited to networks where sensors are more widely dispersed, with greater distances between nodes. In very low density remote applications, cellular connections may even be necessary using the same housing, for deployment in these environments. Sensor configurations using Bluetooth technology (Bluetooth Special Interest Group) is planned.
In addition to temperature, other types of wireless devices are expected to measure parameters such as corrosion, pressure, vibration and others. These new sensor types will have the same look and feel, simplifying use.
Wireless monitoring sensors and supporting application platforms simplify the installation, configuration and maintenance of monitoring systems. These new sensors can be installed and brought online more quickly and cost-effectively than traditional wired transmitters. Given the gains of higher availability and the ability to assign scarce technicians to more valuable tasks, effective automated monitoring strategies can deliver payback in a matter of months.
Ryan Lindsey is a senior IIoT platform manager at Emerson. Edited by Mark T. Hoske, editor-in-chief, Control Engineering, WTWH Media, [email protected].
Keywords
Wireless sensing, IIoT sensing platform, wireless monitoring
Consider this
What aren’t you measuring and monitoring because wiring is too costly? Could wireless industrial sensors help?
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See more details on an IIoT wireless sensing platform.
https://www.controleng.com/products/useful-iiot-platform-reduces-manual-inspection-gaps
Control Engineering provides more about process instrumentation and sensors.
https://www.controleng.com/process-instrumentation-sensors
Control Engineering provides more about wireless technologies.
