In-service monitoring

In considering these benefits, the user should not overlook the constraints in using such fluids. They can be summarized as limited wear and corrosion protection (especially with certain metals), increased leakage due to its low viscosity, limited operating temperature range and the need for additional mixing and in-service monitoring facilities. 

The final step is the selection of preventive maintenance tasks for all components found critical. Maintenance tasks are selected according to a specific selection logic which views all preventive maintenance operation in a ascending order of complexity lubrication, in-service monitoring, checks and tests, complete overhaul and scheduled replacement. 

Structural Health Monitoring (SHM) can be defined as the method by which sensors are utilized to identify and quantify structural integrity through a continuous in-service monitoring process. In this manner, corrective maintenance ean be performed when required before the structure reaches the critical point of catastrophic sudden failure. 

NDT may hence be effective and economic in scientific research, product or process development, manufacturing process control, quality assurance, and in-service monitoring of crucial or high performance rather than mass produced, low cost pol5mier and PMC products. 

The reinforced area was instrumented with special devices and data loggers to measure deformations and tensions, as well as environmental conditions. This allowed the in-service monitoring of the evolution of the behaviour of the composite system. Since then, several Portuguese researchers have been involved in the in-field characterization and health monitoring of the bridge, e.g., Silva (2008). 

In-service testing provides the advantage of examining the corrosion behavior of a metal in the actual service environment. The advantages and disadvantages of some of these tests are briefly described below. More detail can be found in the article titled In-Service Monitoring in Ref 69. Section III—Types of Tests—Seawater, describes further details on seawater testing. 

Almost all known test methods applicable to aqueous solutions [26-30] (see Sections III, IV, and V) have been extensively used for material and design evaluation and in failure analysis of steam cycle materials. Many of these methods have been adapted for field testing. Corrosion variables that need to be known in design and failure analysis are, together with the applicable corrosion test methods, listed in Table 3, Table 3 also lists the corrosion test methods that have been applied for in-service monitoring. 

The new technical field of Diagnostic Engineering aimed at an incipient failure detection and "predictive and preventive maintenance is becoming a part of in-service monitoring [36]. 

In-service monitoring is seldom used in the food and beverage industry except in testing alternatives for known problem areas. 

McFarlane, Smith, Davies, Millustry. In-service monitoring of AGR and PWR Nuclear Safety related Structures in the UK, Institution of Nuclear Engineers, September 1996, Cambridge, UK. 

Provisions should be made in the design of the UHS and its directly associated heat transport systems to permit in-service monitoring and inspection so as to provide adequate assurance of its continued functional capability throughout the lifetime of the plant. 

Causes of failure on many different hoses over a 15 year period are investigated. Each examination was treated as part of a continuing study so that fundamental modes of failure could be identified, and dealt with at a design, manufacturing or in-service stage. Attempts were made to identify non-destructive in-service monitoring to ascertain length of service limits. 

Building a safety case is an increasingly common practice in many safety critical domains [7]. A safety case comprises both safety evidence and a safety argument that explains that evidence. The safety evidence is collected throughout the development and operational phases, for example from analysis, test, inspection, and in-service monitoring activities. The safety argument shows how this evidence demonstrates that the system satisfies the applicable operational definition of acceptably safe to operate in its intended operating context. 

A Safety Case receives its inputs from these lower level Safety Assessments, which are updated only if specifically contracted. For instance, when in-service monitoring has identified an uncorrected assumption or some other deficiency... 

Consider a system that has undergone numerous upgrades and modifications during its operational life. The owner/operator is supposed to be responsible for the safety case and demands safety assessments from contractors/suppliers/system integrators. However, there are few examples in industry of how the various safety assessments conducted by the different contractors are integrated into the operator s safety case, or how in-service monitoring of all these safety assessments is efficiently accomplished. 

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