JUL-AUG 2019

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40 INTECH JULY/AUGUST 2019 WWW.ISA.ORG AUTOMATION BASICS If you can show an auditor or other responsible entity that a noncritical instrument has no effect on product quality, safety, or the environment, then you can claim there is little or no need for periodic calibration. Conversely, you may need to calibrate critical in- struments more often than annually to maintain product quality, process op- eration, or safety. The instrument manufacturer can help determine factors to keep in mind when defining MPEs, and it can help as- sess the plant's installed base. It can also help define ideal calibration intervals. Managing instrument data Data from the installed base analysis should be stored in an asset manage- ment, maintenance management, or instrumentation management software program. One of the major advances in recent years has been the development of instrumentation management soft- ware. These systems contain informa- tion such as spare parts lists, drawings specific to the instrument, original cali- bration data, and certificates. All instrumentation is calibrated by each manufacturer before delivery to the customer, and this calibration data is easily entered into asset management software. Afterward, when a device is re calibrated, its calibration history can be updated and automatically loaded into the asset management system. In many cases, modern instrumenta- tion equipped with advanced diagnos- tics can determine if a problem exists, and condition monitoring or other software can inform the maintenance department via an alarm if a particular device is having problems. This diag- nostic data also feeds into the instru- ment management software, where operators, engineers, and maintenance personnel can review it remotely. For example, diagnostic data from a Coriolis flowmeter can include empty pipe detection, sensor drift, sensor er ror, electronics error, inhomoge- neous mixture error, and ambient and process temperature errors. This data can be used to optimize calibration, diagnose problems, and detect minor issues before they grow into substantial problems. In addition, many flowmeter technol- ogies are incorporating built-in verifica- tion methodologies to qualitatively en- sure and document instrument health. When these verification methodologies are traceable, they can be used to sup- plement the calibration plan. Another recent advance gives access to the information in an asset manage - ment system via mobile devices. From the field, a technician can pull up the calibration history, diagnostic data, troubleshooting instructions, and other information needed to properly diagnose an instrument issue. Deciding when to calibrate Calibration frequency depends on the MPE, the nature of the product being measured, the need for clean-in-place (CIP) operations, the severity of pro- cess impacts, the type of instrument, and other factors. In some cases, it may only be possible to access an instru - ment during a complete process shut- down; in other cases, an instrument might be completely accessible for calibration. Considering the cost of each cali- bration—which may involve shutting down a process to allow removal of the instrument, taking it to an accredited calibration facility, reinstalling it, and starting up the process—it is wise to combine the calibration plan with a plan for spare parts and replacement instruments. Thanks to advances in diagnostics and instrument management software, setting up an instrument calibration plan based on best practices is much easier than in the past. Once set up, the calibration plan will improve opera- tions and save money by making sure all instrumentation is calibrated only when necessary. n ABOUT THE AUTHORS Kyle Shipps is the calibration manager for Endress+Hauser. He has worked in the service depart- ment since 2001 and maintains ISO 17025 accreditations for two calibration laboratories and field calibration services. Shipps has a BS in software engineering and AS in electronic technology. Nathan Hedrick is na- tional product market- ing manager for flow at Endress+Hauser. He graduated from Rose- Hulman in 2009 with a BS in chemical engi- neering. He began his career with Endress+Hauser in 2009 as a technical support engineer. Some asset management systems allow access to instrument information by mobile devices. This maintenance technician gets the data he needs to troubleshoot the level instrument on this tank.

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