Reliability Issues

When we talk about instrument reliability, it is important to understand whether it is related to the samples being analyzed, the lack of expertise of the person operating the instrument, an umeliable component, or an inherent weakness in the design of the instrument. For example, how does the instrument handle highly corrosive chemicals such as concentrated mineral acids Some sample introduction systems and interfaces will be more rugged than others and require less maintenance in this area. On the other hand, if the operator is not aware of the dissolved solids limitation 

To a certain degree, instrument reliability is impacted by routine maintenance issues and the types of samples being analyzed, but it is generally considered more of a reflection of the design of an instrument. Most manufacturers will guarantee a minimum percentage uptime for their instrument, but this number (which is typically -95%) is almost meaningless unless you really understand how it is calculated. Even 

Practical Guide to ICP-MS A Tutorial for Beginners, Second Edition 

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Ibis chapter will discuss various reliability issues. The discussion will kept at a philosophical level rather than getting into a statistical analy The statistical analysis is best left to others equipped with the training, toi and the data. Hopefully, this material will give the reader some comn sense insight into the various considerations involved in the selection applicadon of reliable compressors, their drivers, and auxiliary systems. 

With the opening of the transmission network to all resource suppliers, many marketing entities entered the game in the mid-1990s. Many of these marketers are subsidiaries of already established gas suppliers. Some have been created solely for the electric industry. Still others have been formed from the utilities themselves. All of these etitities arc competition-motivated. Facility planning and reliability issues, while important to their business, are left to other organizations. 

Incidentally, Schottky diodes do not have any reverse recovery current issues, but they do have some body capacitance, which can produce similar effects. However, that fear has always proven to be exaggerated. I have personally not seen any application having a performance issue explicitly related to a bad Schottky. The only exception was a case where the leakage current of the Schottky was so high, it was prematurely tripping the current comparators inside the switcher IC. And there was also a reliability issue once, concerning the dV/df rating of a commercial Schottky. Both these issues are discussed elsewhere in this book. 

Different groups of customers may introduce different requirements due to different levels of awareness of quality assurance and laboratoiy reliability issues. Competent authorities with a responsibility for the implementation of the legislation e.g. health, safety, envirorunental issues, organizations involved in procurements, the industry and individuals may have different requirements. 

This study demonstrates that the nonlinear optimization approach to parameter estimation is a flexible and effective method. Although computationally intensive, this method lends itself to a wide variety of process model formulations and can provide an assessment of the uncertainty of the parameter estimates. Other factors, such as measurement error distributions and instrumentation reliability can also be integrated into the estimation procedure if they are known. The methods presented in the crystallization literature do not have this flexibility in model formulation and typically do not address the parameter reliability issue. 

From the point of view of thin films, efficiency improvements and reliability issues need to be overcome for technology to be able to follow the same curve (with a different breakdown of components, however). 

However, as indicated by Kleinberg (2006) there is the need for a much better prospecting tool than the BSR, due to reliability issues. First, very little gas is required to produce a strong seismic reflector (Domenico, 1977). Second, an apparently continuous reflector does not imply a continuous gas-saturated zone. It is now well established by high resolution seismic techniques that BSRs that appear continuous in conventional marine seismic can actually be because of discontinuous patches of gas (Wood et al., 2002 and Dai et al., 2004). As a final example, the recent drilling of a BSR off the west coast of India failed because the BSR was caused by a carbonate deposit, rather than hydrates (Collett, T Personal Communication, November 6, 2006). 

The implementation costs of FTIR instrumentation, especially for on-line applications can be very high, sometimes in excess of US 100 000. Also, there are issues relative to size, performance and still the physical reliability issues that make FTIR less than acceptable for many areas of application. Furthermore, there is a general desire to make instrumentation much smaller, and even handheld and portable (one example is shown in Figure 4.4). As a result, today we are seeing a number of new competing technologies. In some cases these are direct competition to FTIR, but in others there are often compromises between size and/or performance, and overall versatility. FTIR is a very versatile approach to spectral measurement. However, such versatility is often not required for specific applications, and it is in such cases that alternative technologies can often excel. 

An important reliability issue in nitride LEDs is electrical static discharge (ESD) survivability. Both commercial DH LED products on sapphire include a warning of the sensitivity of these devices. The ESD survivability of the DH GaN SiC LED chip has recently been improved and is far superior to that... 

R. McConnell, Large-Scale Deployment of Concentrating PV Important Manufacturing and Reliability Issues, Proceedings of the First International Conference on Solar Electric Concentrators, New Orleans, Louisiana, NREL/EL-590-32461, May 2002. 

Hair Analysis for Organic Analytes Methodology, Reliability Issues, and... 

A number of studies addressing these reliability issues have been conducted at Honeywell (8,21) and elsewhere (11,12,22-24). 

Compatibility with The Substrate and Dielectric The adhesion layer in the blanket-W case now proves to be an advantage. Most commonly this is sputtered TiW or TiN. The contact resistance and reliability issues of these materials have been well studied and are under control. Thus for blanket tungsten no additional problems are expected here. In the case of selective tungsten a completely new interface is created, namely that between silicon and the tungsten. Also, because of the wide variety of substrates and... 

A disadvantage of this approach is that it obviously will not work for the fill of contacts to silicon (however, see Yeh et al.185). This implies that two plug techniques are necessary to overcome the reliability issues, one (blanket) for the contacts and one (pillars) for the vias. 

Owing to the extensive infrastructure related to the chosen materials base (silicon), and the relative ease in which silicon based microsystems can be produced, a convenient approach to overcoming some of these reliability issues is to apply coatings for stiction, friction, and wear control to the devices after they are produced. This is analogous to painting buildings or automobiles after they are constructed to make them more weather resistant. Therefore, facile and effective coating processes that satisfy the needs of the microsystems for reliable performance have been developed. 

Magnetic principles are used, as well as inductive, capacitive, and optical sensors. In many applications, where cost requirements predominate over performance and reliability issues, simple potentiometers are often found. The market volume in 2002 is about 150 million units and will approach 300 million units, worth more than 1700 million, in 2008. 

This section describes a methodical procedure that allows reliability issues to be approached efficiently. MEMS reveal specific reliability aspects, which differ considerably from the reliability issues of integrated circuits and macroscopic devices. A classification of typical MEMS-failure modes is given, as well as an overview of lifetime distribution models. The extraction of reliability parameters is a Tack of failures situation using accelerated aging and suitable models. In a case study, the implementation of the methodology is illustrated with a real-fife example of dynamic mechanical stress on a thin membrane in a hot-film mass-airflow sensor. 

Therefore, for commercial suppliers, reliability issues have come more and more into the focus of engineering and research activities. Reliability has become a key parameter for the success of MEMS in a market with distinct safety implications [2-7]. 

The manufacturing processes represent the link between the reliability issues of the microstructure on one hand and those of assembly and packaging on the other. The process flow must take into account, for example, the impact of the applied temperature range, pressure, and media on the sensor structure, which at the time of packaging is already completed. Dicing of sensor structures that include delicate elements, such as freestanding cantilevers or thin membranes, is usually very critical and requires some kind of protection which can be effectively provided by zero-level packaging on the wafer scale. 

Note On the topic of beads, note that beads also sometimes have been put in series with the mosfet. But we should not put any such bead in the source. If we do so, then during crossover transitions, the source pin (with bead) can develop spikes. And since the gate is referenced to the source, not the drain, this can lead to a spurious turn-on, resulting in reliability issues. Therefore, a bead, if necessary, should be placed only on the drain side of the mosfet. True, this extra uncoupled inductance can also cause a small spike in principle, but in practice, that is rarely an issue. For the same reason, if we want to monitor the current in the mosfet by means of a current probe, we should place the loop of wire (to slip the probe tip on to) on the drain side, never on the source. 

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