Range dynamic

Like sensitivity, LOD depends on the inherent sensitivity of the device itself, as well as the kinetics and thermodynamics of the coating-analyte interaction and the quantity (thickness and/or surface area) of coating available. Unlike sensitivity, however, LOD also depends on the system noise level. The LOD is expressed in terms of the ratio [response when analyte is present]/[noise level when there is no analyte present]. Commonly, LODs are denned as signal-to-noise (S/N) ratios of two or three, corresponding roughly to situations where the signal exceeds the noise at statistical confidence levels of 95% and 99%, respectively [91]. Thus, in the latter case, the LOD can be defined as 3N/sensitivity. The LOD is expressed in units of concentration (e.g., M, fig/L, or iqnn). 

In the somewhat rare instance that the coating (even when loaded with analyte), remains highly elastic, mass loading may be the only operative interaction mechanism. In this case, as the total coating-plus-anaiyte thickness reaches and exceeds several percent of one acoustic wavelength, the mass sensitivity deviates significantly from that derived from perturbation analyses for acoustically thin films, and is difficult to predict. 

In the short term, minimal noise and short-term drift are the goals. Noise has a detrimental effect on the LOD and on the precision of the response. Short-term drift, often associated with short-term changes in ambient parameters such as temperature, pressure, and relative humidity, can exceed oscillator noise, in which case drift dictates the LOD. While it is possible to partially compensate for noise by averaging several consecutive data points, this is mote difficult for short-term drift. 

Some of the effects of both long- and short-term drift (not noise) can be cor- 

This is the abihty of a dog trained to detect a specific target to also correctly detect similar but not identical targets. Table 1 shows that dogs trained on only one smokeless powder, BuUseye, have on average a 52% chance of detecting a powder from another manufacturer, IMR 4064. 

If the dogs are trained on two different smokeless powders, BuUseye and Red Dot, which both happen to be AUiant products, the dogs chances of detecting IMR increase to 61%. If they are trained on three smokeless powders, stiU aU AUiant powders, their abUity to generalize increases so that they have, on average, a 71% 

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Here presented results were acquainted predominantly by one-channel ten-level AE analyser IOC of the AED Laboratory Brno firm. This device is equipped by ten window threshold levels, defined fi-om top and bottom, the tenth level has not limitation fi-om top. Total dynamic range is 40 dB. The analyser enables continuous observation of total number of counts Nc, or number of counts per time unit and similar. Everything may be observed both in lull measured range and in individual levels. Range of measuring interval is SO ms up to 2500 ms. 

A SQUID [2] provides two basic advantages for measuring small variations in the magnetic field caused by cracks [3-7]. First, its unsurpassed field sensitivity is independent of frequency and thus dc and ac fields can be measured with an resolution of better than IpT/VHz. Secondly, the operation of the SQUID in a flux locked loop can provide a more than sufficient dynamic range of up to 160 dB/VHz in a shielded environment, and about 140 dB/>/Hz in unshielded environment [8]. 

In order to realise such a high dynamic range, either a local compensation coil at the location of the SQUID [9] or a gradiometric excitation coil like the double-D coil have to be used. In case of the electronic compensation, the excitation field and the response of the conducting sample is compensated by a phase shifted current in an additional coil situated close to the SQUID-sensor. Due to the small size of this compensation coil (in our case, the diameter of the coil is about 1 mm), the test object is not affected by it. 

The geometric compensation by means of a gradiometric coil is realised by placing the SQUID exactly between the two halfs of the coil, in order to detect only the response of the sample. In both cases we could achieve a reduction of the excitation field at the location of the SQUID of up to 1000. Electronic and geometric compensation together leads to an improvement of six orders of magnitude in the dynamic range, compared to a system without excitation field compensation. 

To carry out digital demodulation, it is necessary to digitize the signal. As ET signals require a great dynamic range, the standard in new instruments is 16 bits. 

To evaluate the image quality of the processing system, one can determine classical parameters like spatial resolution, contrast resolution, dynamic range, local and global distortion. Guidelines for film digitization procedures have been well described now. Furthermore, a physical standard film for both equipment assessment and digitization calibration and control, will be available in a next future (4). 

When the grey level dynamic range in the image processed is small, usually because of a poor illumination or a non uniform lighting, it s possible to increase this dynamic range by a histogram transformation. This transformation affect the intensity distributions and increase the contrast. 

Potential difference created between potential electrodes is amplified in DA (80 dB). CA is used to bring dynamic range of the signal into line with ADT, and to eliminate high frequency interference. 

Evaluation of results (new setting of amplitude threshold in 2 dB steps over the entire dynamic range +/- 12 dB, distance measurement in top and side view)... 

The easy and convenient postprocessing of test findings enables an exact survey of flaws, enlargement of any zones requested, and shifting of the recording threshold within the recorded dynamic range of 24 dB. 

LOG Logarithmic amplifier with 60/100 dB dynamic range without gain setting 0.1 to 10 MHz (-3 dB)... 

The HILL-SCAN 3020LOG with a logarithmic amplifier provides A-seans with a single-shot dynamic range of 100 dB. 

Acoustic foremnners appear as ground vibrations in the range from 0,1 to 50 Hz with the amplitudes from 10 to 10 m (dynamic range is 160 dB). To control these parameters a large number of earthquake-shock recorders based on different principle of operation are manufactured... 

The method covers the full dynamic range of linear velocities from a few centimetres/second to over 100 meters/seconds with one and the same instrumental set-up. Only the amount of tracer used per injection is varied. 

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