Drift measurement

ASAE, Procedure for Measuring Drift Deposits from Ground, Orchard and Aerial Sprayers, Standard No. S561, American Society of Agricultural Engineers, St. Joseph, MI (1997). 

Neutral molecule densities were calculated from the measured product ion intensities using the appropriate reaction rate constants and the measured drift times of H30+ (1.06 x 10 3 s) and H30+ (H20) (1.11 x 10 3 s) ions with the following equation,... 

Figure 1. Dunphy experimental layout and sampling scheme used to measure drift and deposit under various meteorological conditions.

Hall effect measurements indicate mobilities of— 10-1 cm2 V-Isec-1 for both electrons (Dresner, 1980) and holes (E>resner, 1983). Tiedje et al. (1981) have measured drift mobilities of 1 cm2 V-1 for electrons and 10-3 cm2 V-1 sec-1 for holes. However, Silver et al. (1982) have estimated that the electron mobility is s 100 cm2 V-1 sec-1 by using the reverse recovery technique. 

Fig. 3.11. Schematic diagram of the time-of-flight apparatus for measuring drift mobility.

The titanium content of the catalysts was determined by AES-ICP and the carbon content by total combustion in oxygen at 1050°C followed by an acidimetric coulometry measurement. DRIFT spectra of uncalcined samples were measured in inert nitrogen atmosphere conditions on a Nicolet Impact 400 D FTIR spectrometer within the spectral range of 4000 - 400 cm with a resolution of 2 cm and the number of scans equal to 64. 

A sophisticated optical sorting machine will track the average colour of the product so that, even though the average product colour may change with time, the machine will continue to remove only the predefined abnormal particles. Optical sorting machines are often provided with a white calibration plate which is either manually or automatically placed in the optical view at user-defined intervals. The machine is then able to correct for any measurement drift that has occurred. 

In this work we tried to create conditions to deposit MSA on the hydroxylated surface of a-alumina in dense silica layers. The surface-sensitive electrokinetic measurements, DRIFT, SIMS, and XPS, show that the coating grows by deposition of molecular units on the surface of the alumina, whereas TEM, XPS, and surface area measurements show that thick, nonporous silica coatings can be grown. Characterization of particles coated with submonolayer or thicker MSA give insights into the nature of the coatings and the deposition mechanism. 

Cu(I)-ZSM5 (MFI). Calculated IR frequencies were found to be in good agreement with measured DRIFT spectra. 

Determination of cross-sections. The ion motion within the TWIMS device is complex and not yet understood fully. The direct calculation of cross-sectional values from the measured drift times is not yet possible. As... 

Temperature also directly affects the observed peak widths in the IMS experiment. Specifically, as the temperature of the drift gas is lowered, the extent of ion diffusion is also diminished, resulting in both an increase in drift time and a decrease in the ATD (as per a Maxwell-Boltzmann distribution of speeds). An underlying motivation for cryogenic IMS is to increase the resolving power, R, as defined by the measured drift time divided by full width at half maximum (FWHM) ... 

Figure 16.3c contains a combined map of mass versus collision cross section and represents a diverse sampling of biomolecules (n = 951). Note that the mobility data in Figure 16.3c is depicted as CCS as opposed to measured drift times (Figure 16.3b). Because the transformation of drift time data to CCS is nonlinear due to the inclusion...

Fig. 6 shows sensitivity variation with density, but with using correction which has calculated from percentage error. It should be noted that measurement drift, which represent the amount of deviation from true values in measurement procedure, in each range of density is different. Using the average of drifts values to correct the measured HMDs, a promising stability of sensitivity can be... 

Temperature measurement drift - A reading change (error), with time, of a target with nonvaiying temperature, which may be caused by a combination of ambient changes, line voltage changes and instrument characteristics. 

---