Measuring time

With the use of Cs source tomographic layer-by-layer study of nuclear fuel within a range of 5 to 12 g/sm is conducted. In the specialized tomograph the initial information measurement time is 5-30 min, the tomograms restoration time is 4-10 min. The sensitivity to a various density is about 5% when detecting local areas with a diameter exceeding 0.5mm. 

An important extension to the simplest upconversion experiment at a single detection frequency M2 is the practice of measuring time-resolvedfluorescence spectra, that is, the shape of the fluorescence spectrum... 

NMR spectroscopy is probably the singly most powerful technique for the confirmation of structural identity and for stmcture elucidation of unknown compounds. Additionally, the relatively low measurement times and the facility for automation contribute to its usefulness and industrial interest. 

Ions in a TOF analyzer are temporally separated according to mass. Thus, at the detector all ions of any one mass arrive at one particular time, and all ions of other masses arrive at a different times. Apart from measuring times of arrival, the TDC device must be able to measure the numbers of ions at any one m/z value to obtain ion abundances. Generally, in TOF instruments, many pulses of ions are sent to the detector per second. It is not unusual to record 30,000 spectra per minute. Of course, each spectmm contains few ions, and a final mass spectrum requires addition of all 30,000 spectra to obtain a representative result. 

Cross Correlation. Considerable research has been devoted to correlation techniques where a tracer is not used. In these methods, some characteristic pattern in the flow, either natural or induced, is computer-identified at some point or plane in the flow. It is detected again at a measurable time later at a position slightly downstream. The correlation signal can be electrical, optical, or acoustical. This technique is used commercially to measure paper pulp flow and pneumatically conveyed soHds. 

The spatial resolution of the Raman microprobe is about an order of magnitude better than that obtainable using an infrared microscope. Measurement times, typically of a few seconds, are the same as for other Raman spectrographs. To avoid burning samples, low (5—50-mW) power lasers are employed. 

Fig. 2. Assay reaction curves for (a) substrates, (b) enzymes, and (c) enzymes exhibiting a lag phase or reduced reaction rate where t is measurement time.

The temperature in the hottest part of the kiln is closely controlled using automatic equipment and a radiation pyrometer and generally is kept at about 1100—1150°C (see Temperature measurement). Time of passage is about four hours, varying with the kiln mix being used. The rate of oxidation increases with temperature. However, the maximum temperature is limited by the tendency of the calcine to become sticky and form rings or balls in the kiln, by... 

Figure 19-7 shows off potential measurements as an example, in which the 100-mV criterion, No. 3 in Table 3-3, as well as the potential criterion t/ ff < is fulfilled. It has to be remembered with off potential measurements that according to the data in Fig. 3-6, depolarization is slower with age, so that the 100 mV criterion must lead to errors with a measuring time of 4 hours. Off potential measurements should be carried out after commissioning at 1-, 2-, 6- and 12-month intervals and then annually. 

An optical detector with appropriate electronics and readout. Photomultiplier tubes supply good sensitivity for wavelengths in the visible range, and Ge, Si, or other photodiodes can be used in the near infrared range. Multichannel detectors like CCD or photodiode arrays can reduce measurement times, and a streak camera or nonlinear optical techniques can be used to record ps or sub-ps transients. 

The counting time for one pixel, and the number of pixels, determine the measurement time for one image. For low concentrations of the elements of interest the Pois-... 

Reduction of the measurement time for element distributions is possible by simultaneous detection of several masses. This can be achieved only by use of a magnetic sector field spectrometer with Mattauch-Herzog geometry [3.49] (Fig. 3.20) and parallel detection of up to five masses by mechanically adjusted electron multipliers. 

Fig. 3.24. Di rect-imaging mode SIMS image of a passivation layer on a niobium alloy [3.54], Boron enrichment at the interface is not visible with EPMA. Measurement time 10 s image diameter 150 pm primary ions OJ primary energy 5.5 keV.

The advantage of the imaging mode is fast data acquisition. Because all pixels are projected and detected simultaneously the measurement time for one distribution is extremely low. 

In scanning mode the sequential detection of single pixels (picture elements) and voxels (volume elements) results in long measurement times in practice, therefore, only small volumes (10 x 10 x 1 p,m ) can be measured [3.56]. 

The calculation procedures just described are methods for predicting shortterm GLC s for single stack cases. In the calculation of short-term GLC s it is as sinned that meteorological conditions are constant throughout the measuring time period. Short-term time periods are usually considered to be 1 hour or less. The averaging times for the various methods discussed are as follows ... 

Component Range 1 Range 2 Typical detection limit, 1 -s measuring time... 

Reaction is too fast to measure. Time for complete solvolysis of the substrate. 

Zeit-lose, /. colchicum. -mass, n. measure of time (Music) time, rhythm (Gram.) quantity. -massstab, m. time scale, -messer, m. chronometer, time piece, watch, clock, -messung, /. time measurement timing, -puukt, m. point of time, moment, zeitraubend, p.a, time-consuming. 

If the initial rate of growth of nuclei is slower than the constant value subsequently attained, the above expression remains applicable [28] provided that appropriate subtraction from the measured time is included, viz. 

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