Field measuring methods

In the laboratory, soil water content is measured by drying in the oven and with a pressure plate apparatus. Drying soil can change the form and species of components present, and for this reason, most soils are air dried carefully or at temperatures only slightly above room temperature before analysis. A number of different field measuring methods are used mostly to determine the amount of water available for plant use. 

Rehm, B. W. Stolzenburg, T. R. Nichols, D. G. Field Measurement Methods for Hvdrogeologic Investigations A Critical Review of the Literature. EPRI-EA-4301, Electric Power Research Institute, Palo Alto, CA, 1985, 328 pp. 

Development of new methods and instrumentation became one of the core activities of the SM T programme. These developments concern innovative instruments necessary to improve the quality of measurements in particular sectors (e.g. on-line measurement techniques, field-measurement methods etc.) [10]... 

Od-site investigations Correlation between liquefaction phenomena observed and soU properties measured in the field. Measurement methods of the resistance to liquefaction using cone penetration (CPT) and standard penetration (SPT) tests have been developed. 

Grediac M. (2004) The use of full-field measurement methods in composite material characterization Interest and limitations, Composites-Part A Applied Science and Manufacturing, 35(7-8), 751-761. 

D similarity search methods are quite well developed. Thus, methods which attempt to find overlapping parts (atoms and functional groups) of the molecular moieties studied were reported first [31]. As discussed above for the case of 2D searching, these methods are of combinatorial complexity. To reduce this complexity some field-based methods have been introduced. In this case, the overlap of the fields of two structures is considered as a similarity measure. 

The 2eta potential (Fig. 8) is essentially the potential that can be measured at the surface of shear that forms if the sohd was to be moved relative to the surrounding ionic medium. Techniques for the measurement of the 2eta potentials of particles of various si2es are collectively known as electrokinetic potential measurement methods and include microelectrophoresis, streaming potential, sedimentation potential, and electro osmosis (19). A numerical value for 2eta potential from microelectrophoresis can be obtained to a first approximation from equation 2, where Tf = viscosity of the liquid, e = dielectric constant of the medium within the electrical double layer, = electrophoretic velocity, and E = electric field. 

Field Scanning Methods In these techniques, the particles to be measured are examined collectively, and the signal from the assembly of particles is deconvulated to generate a size distribution. 

Field coating of welds has always presented problems. Straw and jute with a greasy material was employed in 1910, but this later saponified in the soil. By chance the pharmacist Schade of Berlin learned of this problem and recommended the use of petroleum jelly in a bandage-like application. Hot-applied bitumen bands, as used by pipe works since 1928. proved to be most durable. Since 1930, electrical measuring methods have played an important part in research into insulation bands and pipe coverings carried out by the Gas Institute in Karlsruhe, the present-day Engier-Bunte Institute 18). 

It would be an understatement to say that the gas expander turbine forms a major part of the power train. Evaluating off-design performance for the expander installed in the Sinopec Jinan Oil Refinery is presented as an example of an appropriate evaluation method. It should be noted that calculations are based on actual field measurements and plant experience. 

These types of stoichiometric calculations are commonplace and can provide reliable estimates for the material balance. As with any calculation method, one should list the assumptions to qualify the accuracy of the estimate. Limited field measurements can always be done later to verify the estimated emissions. 

A detailed method of determining pressure coefficients is to perform experiments with a wind tunnel facility. Cochran and Cermak compared wind tunnel pressure coefficient measurements with field measures on a test building and found excellent results, with the exception of small areas beneath the vortices near the upwind roof corner for winds approaching at 45 . For infiltration and natural ventilation designs, wind tunnel results should be sufficiently accurate. 

ASTM E783-84. 1984. Standard Method for Field Measurement of Air Leakage through Installed Exterior Windows and Doors. American Society for Testing and Materials, Philadelphia. 

The simplest way to calibrate a hygrometer is to use ambient air. The humidity of ambient air is measured using both the calibrated meter and the reference meter. A simple psychrometer or an Assmann hygrometer can be used as a reference. Provided the air conditions are stable, this method is used to check hygrometers in field measurements and other not too demanding purposes. 

The theoretical framework for near-field imaging, on the other hand, is not as straightforward as that for the far-field optical measurements. This is primarily because the effects of perturbation from the near-field probe on the optical characteristics of the samples are not well known. Further developments in theoretical treatments and practical and precise simulation methods for realistic near-field measurement systems are desired. 

In addition to the requirements regarding traceability of measurement results, the measurement methods employed should represent "state-of-the-art in the particular field. Failing to do so would lead to a reference material with an uncertainty that has become too large to serve as a quality control. The better the methods perform in terms of uncertainty and traceability, the better the reference material will serve the interests of the (potential) users. 

Residue chemists will need to continue to improve the speed of analysis. In situ measuring methods that can be applied in the field or processing plant or retail outlet would be particularly useful, so that decisions can be made rapidly which might avert toxicity to humans or wildlife, potential residue problems or unnecessary economic loss. 

Field measurement of soil resistivity using the Wenner four-electrode method... 

Direct shear test of soils under consolidated drained conditions pH of soil for use in corrosion testing Field measurement of soil resistivity using the Wenner four-electrode method Optimum S03 in portland cement... 

---