Measuring methods for

The basic standard for cathodic protection was laid down for the first time in DIN 30676 to which all the application areas of the different branches of protection can be referred. In this the most important point is the technique for accurately measuring the object/soil potential [58]. The usual off-potential measurement method for underground installations has been slowly implemented and enforced in Europe since the 1960s [59]. 

On other hand, we found a good correlation between the results by the present method and those by the Terradex detector. However, the mean value obtained by the Terradex detector were about twice those by the present method. The reasons for this significant difference are unknown and may be due to errors in the calibration experiments and in the conditions during the measurements. In the calibration experiments the effect of existence of thoron in the chambers could be one of the reasons. As regards the condition in the measurements, methods for subtraction of background tracks and deposition of dust onto the bare detector could be candidates. However, we do not have enough data to determine the reasons for some of this difference. 

Y. Hong and J. Kanicki, Integrating sphere CCD-based measurement method for organic light-emitting devices, Rev. Sci. Instrum., 74, 3572-3575, 2003. 

In the late 1980s, improvements in the measurement methods for trace metals in seawater lead to the observation that dissolved iron concentrations in the open ocean are... 

A number of significant oxygenated organic particulate compounds and gas-phase free radicals are formed by the reactions of gas-phase hydrocarbons (see Table 6-1 and (Chapter 2). The measurement methods for these substances are complicated and in the research stage. Their description is beyond the scope of this chapter. It is of major importance to develop methods for measuring hydroxyl and peroxyhydroxyl radicals, as well as the various oxygen species formed with ozone (see Chapter 12). 

Among the most often used stress measurement methods for crystalline films is determination of the change in interplanar spacing of the crystallites in the film by x-ray diffraction. X-ray determination of near-surface strain and stress in bulk materials has a long history, dating back to the very early period of x-ray powder diffraction measurements and is a well-established technique. 

Velocity Profile Effects Many variables can influence the accuracy of specific flow measurement methods. For example, the velocity profile in a closed conduit affects many types of flow-measuring devices. The velocity of a fluid varies from zero at the wall and at other stationary solid objects in the flow channel to a maximum at a distance from the wall. In the entry region of a conduit, the velocity field may approach plug flow and a constant velocity across the conduit, dropping to zero only at the wall. As a newtonian fluid progresses down a... 

However, Fraser et al. (1998) noted that this canister sampling technique may underestimate the methyl-naphthalenes. Thus, their methylnaphthalenes/naph-thalene ratios were lower than those obtained by Arey et al. (1989a) using Tenax-GC solid adsorbent. This may be due to significant adsorption of the methyl isomers to the canister (Arey, personal communication). Zielinska and co-workers (1996) evaluated measurement methods for VOCs up to C2() emitted from motor vehicles and reported that C8-Cl2 hydrocarbons were more stable on the Tenax cartridge than in canisters. Similar problems with canister sampling for organics are discussed in Chapter ll.A.4e. 

Fluorescence is the basis of a number of measurement methods for atmospheric gases. In the case of SOz, for example, a Zn (213.8 nm) or Cd (228.8 nm) lamp is used to excite the SOz and the fluorescence in the 200- to 400-nm region is monitored (Okabe et al., 1973 Schwarz et al., 1974). Again, this technique works for those species whose excited states are sufficiently... 

Continuous Measurement Methods for Trace Cases and Aerosols. Ozone. Three basic types of ozone instruments have been used in aircraft the ultraviolet photometric method and two chemiluminescent techniques measuring, respectively, light emitted from the reaction of 03 with ethylene and light emitted from the reaction of 03 with NO. Ultraviolet absorption photometry is one of the preferred methods for measuring 03 from aircraft because of the stability and reliability of commercially available instruments. The method is specific for 03 provided there are no immediate... 

Useful Hardness Measurement Methods for Hard Materials in Grit Form 273... 

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