Many industrial plants and processes rely heavily on a large range of process instrumentation. From water treatment plants to petro-chemical facilities, they all depend on flow meters, temperature and pressure transmitters and gas and liquid analysers to give accurate measurement and control. Although the overwhelming focus of plant managers will be on the health and correct operation of the process, the instruments that provide the data also need attention. They must continue to operate reliably and accurately if the processes are to run as desired. This means that the health of the instruments themselves should be a major priority. Smart devices measure own condition Advances in technology have seen today’s process instrumentation become largely digitally based. These instruments produce a wealth of information about the process Maintenance Matters Focus on: Condition Monitoring 14 | Plant & Works Engineering www.pwemag.co.uk October/November 2023 Unlocking operational excellence PWE takes a look at how developments in instrument condition monitoring can unlock operational excellence. parameters they are designed to measure – they also use their digital features to report about their own performance and accuracy. Commonly known as condition monitoring, many modern devices can check their own circuits for errors and other issues, help technicians conduct calibration and evaluate their own performance. Some of the benefits of device condition monitoring include keeping constant track of the health of measurement devices, often bringing the ability to share health check reports with the device vendor. Experts at the device supplier can then offer service recommendations based on the device’s health status and even offer remote assistance. Some providers take data from their devices and offer a full online condition monitoring system to enhance decision-making, putting information at users’ fingertips. Reduced maintenance is another major benefit. Although many instruments are designed to minimize maintenance effort with self-cleaning and self-optimizing of active components, an accurate assessment of the condition of the device allows users to move to a predictive maintenance regime, avoiding the need to conduct scheduled maintenance that may not be necessary. This can be particularly useful if the device is in a remote area, is difficult to access or is part of a process that could pose risks to health and safety. Another benefit is achieving maximum up time of the device. This is particularly important for critical operations such as gas emissions monitoring systems, which are becoming much stricter in many countries. For example, in the countries with the most restrictive regulations, operations may have only a maximum of 10 invalid minutes per half hour, a maximum of 5-6 invalid half hour averages per day, or a maximum of 10 invalid days per year. Further options for condition monitoring of instruments include remote monitoring that can send condition alerts direct to a manager’s smartphone or tablet, keeping them constantly aware of how critical devices are performing. Gaining all the benefits The basic first requirement when seeking to taking advantage of these abilities is to get the right communications with the device. Most measurement devices are digital, though many applications continue to use the tried and tested 4-20mA current loop. Some of the most advanced 4-20mA measurement devices also offer HART communications, a bi-directional communication protocol that sends data to and from intelligent field instruments and host systems. An ability to interrogate the device is the next step and two common methods exist for interrogating device data. The first is inbuilt condition monitoring and diagnostics based on the NAMUR NE 107 standard. NAMUR NE 107 makes it easier for technicians and other process personnel who need to deal with alarms by categorizing internal diagnostics into four standard status signals — failure, function check, out of specification and maintenance required. Each of these status signals can also contain greater detail. With a failure signal, for
RkJQdWJsaXNoZXIy MjQ0NzM=