Representative Monitors

A CMP process may fall into one of the two categories one is a blind process such as ILD CMP and the other is a recess process such as metal CMP. In the 

Friction change detected by motor current [31 ] This is one of the most popular recess process methods. In the example of W CMP, friction forces differ for W metals, barrier metals such as Ti and/or TiN, and substrates. These friction differences can be detected by the motor current of a wafer carrier or a table. 

Vibration-level change detected by vibration sensor [32[ Carrier vibration changes when different materials are polished or when different topographies are polished. This method can be used for both blind and recess processes. 

Eddy current induced by magnetism [33[ This is used only for metal polishing. When metal thickness changes, the eddy currents induced by magnetism also change. This system also measures metal thickness. 

Optical detection [34] The reflection difference generated by different materials is detected. This method is applicable to recess processes. 

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To put these data in perspective, it is important to point out that they merely imply an exhaustive biodegradation of secondary alkanesulfonates and do not represent monitoring results. 

Reductions in apparent LNAPL thickness in the subsurface have been effected over most of the site. In general, apparent thickness after 1 year were reduced 30 to 40% to those apparent thicknesses measured prior to recovery. The reduction in apparent thickness in a representative monitoring well with time is shown in Figure 12.3. However, in one area of the site, hydrocarbon thicknesses actually increased... 

Table I. Representative Monitoring Equipment for Particulate Matter for Indoor Air Quality Samples...

Two main networks are differentiated in the USA the state and local air monitoring stations (SUAMS) and the national air monitoring stations (NAMS). The two networks mainly differ in their requirements with respect to area of coverage with more, smaller-scale representative monitoring sites within the SLAMS. The objectives, primarily for SLAMS, as laid out in CFR 40 [13] are to ... 

Butte, W., Hoffmann, W., Hostrup, O., Schmidt, A. and Walker, G. (2001) Endokrin wirksame Substanzen im Hausstaub Ergebnisse eines reprasentativen Monitorings. [Endocrine disrupting chemicals in house dust results of a representative monitoring]. Gefahrstoffe-Reinhaltung der Luft, 61, 19-23. 

The measured concentration of 1,1,1-trichloroethane in urban air usually ranges from 0.1 to 1 ppb however, levels <1,000 ppb have been observed in large urban areas or near hazardous waste sites. Representative monitoring data on the concentration of 1,1,1-trichloroethane in air can be found in Table 5-3. Rural levels of 1,1,1-trichloroethane are typically <0.2 ppb. The long atmospheric lifetime of 1,1,1-trichloroethane allows the compound to be carried a considerable distance from its initial point of release detectable levels have been measured in numerous remote areas throughout the world and are shown in Table 5-3 (Class and Ballschmiter 1986 DeBortoli et al. 1986 Guicherit... 

Europe has been always behind the US in relation to MTBE groundwater contamination. MTBE studies only started in Europe in the early 1990s. However there still remains a lack of representative monitoring data, especially for the Southern and Eastern European countries. The EU-funded project Water Catchment Areas Tools for Management and Control of Hazardous Compounds (WATCH), which lasted three years from April 2001 up to April 2004, stimulated EU research in this area. 

By the year 2000, selective monitoring points for indoor air at various types of residences involving different fuels is to be undertaken. By 1995 10-20 representative monitoring points for cities and rural areas will be selected to carry out this work. 

In the Drinking Water Directive 98/83/EC, the parametric value (PV) for lead is 10 ig . The parametric value refers to water as it emerges fi om the customer tap, assessed on the basis of representative monitoring (Note 3). Note 3 is as follows ... 

Some Representative Monitoring Programs for Water, Soil, and Biota... 

Whether representative monitoring or random sampling are conducted, the purjxjse remains the same—to determine if the exposure of any employee is above the action level. If the exposure of the most exposed employee is less than the action level and the STEL, regardless of how the employee is identified, then it is reasonable to assume that measurements of exposure of the other employees in that operation would be below the action level and the STEL. 

Answer Since the teflq)erature cycling Is usually the result of a series of local turnarounds and power changes In certain parts of the pile> the only way to prevent cycling is to maintain an even flux distribution over the. various sections of the reactor. Even flux and temperature distribution can be maintained only through the correct interpretation of representative monitoring data, which includes adequate frequency and sampling ... 

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