Criticism of NeSSI mechanical systems have included higher initial cost, inability to troubleshoot at a component level (due to compact/intensive spacing), and the lack of performance data associated with the use of elastomeric seals in long term installations. From a design perspective, it may be difficult to design a modular, mechanical system which meets the needs of the diverse process applications found in industry. Development of the NeSSI-bus has been an iterative exercise, and it will need the close cooperation of both component and analyzer manufacturers to make their equipment NeSSI-bus compliant. At this time, there are missing elements such as a low cost, low power flow sensor which is capable of providing a continuous reading of sample system flow as well as a proportional, miniature control valve.
The predicted impact of NeSSI systems are as follows:
* Adoption of a universally accepted method of protection (intrinsic safety) for sample systems will globalize and harmonize system design and help overcome geographical restrictions currently mandated by various electrical certification/approval bodies such as Factory Mutual (FM) and Underwriters Laboratories (UL), ATEX (Europe), GOST (Russian Federation) and Canadian Standards Association (CSA).
* Analyzer technical staff will have the capability of accessing the status of all the key indicators of analytical sample system performance both locally and remotely. Predictive rather than preventive maintenance can be performed and remote diagnostics and graphical user interfaces are the norm. Analyzer rounds will be eliminated. Analyzer systems will become more reliable and trustworthy. The analyzer technician will have the power to configure a sampling/analytical system, as he/she desires using the smart applets. The adjustable wrench and screwdriver will be replaced with software.
* Molecular management meaning tighter process control by more analysis of the chemical processes - will become feasible with better, faster, less costly and more abundant analysis. This will help reduce manufacturing energy costs and minimize environmental emissions in the process industries.
Since its debut in 2000, NeSSI the mechanical portion has seen gradual but steady acceptance in industry. Currently, there are three major commercial suppliers of NeSSI compliant mechanical systems along with dozens of components available for mounting on these systems. There is also a growing list of companies implementing NeSSI systems in their manufacturing and pilot-plant facilities. Recently, two of the largest suppliers of process analyzers have committed to supporting NeSSI hardware and the development of the intrinsically safe NeSSI-bus communication into their products. NeSSI is gaining status as a de facto standard for many process sampling system applications.
NeSSI (Generation I) acceptance has spread beyond its initial chemical and petrochemical industry roots to find applications in the automotive, food, and pharmaceutical industries, as well as applications as an analytical development system in research laboratories. Generation II electrical systems are now close to commercialization with the first industrial systems scheduled for operation in 2008.