Measurements system

The proposed measurement system consist of measuring impedance variations, resistance and inductance, using a coil surrounding a cylindrical hallow sample, in with standard defects were created homy a variable length and width... 

The measuring system composed of the Wirotest type equipment, the direction probe and reference sample are subject to calibration while using a strength machine. 

To prevent rejects, retouching and to reduce cost of conservatively more than enough applied powder in powder coating processes a handy measurement system allowing to determine the... 

In order to be able to reduce prices, even more and more test- and measurement systems are integrated on PC-boards. The powerful and inexpensive PC eomponents can be directly u.sed for these (virtual) instruments. The limited dimensions of the PC boards require a reduction to the absolute necessity of the electronic components. Analogue signal proeessing must carried out by software as far as possible. 

The pulser/receiver HILL-SCAN 30XX boards satisfy DIN 25450. Typical applications are ultrasonie imaging systems for nuclear power stations and for aircraft, material characterization, transducer qualification, replacement of portable flaw detectors (inspections of welded joints), inspection of new materials, measurement systems with air eoupling. ... 

These initial considerations were promising for an eccentricity measuring system. To investigate the practical possibilities a series of problems had to be examined, such as transducers and equipment, demand to tube guidance, coupling and measurement velocity. 

Evaluation and calibration. A piece of tube was rotated around its own axis during four channel wall thickness mea.surements (Figure 7). The four traces are not identical A rotation apart as should be expected. The calibrations of the four equipment s from the manufacture was not the same. Especially one of the traces has less dynamic than the other three. Based on these observations a dynamic calibration system was suggested using a tube, which could be rotated around its own axis in the measuring system. The values should be verified using traditional mechanical measurement around the tube circumference. The prototype system was permanently installed in the workshop at the production hall. Experimental work was more difficult under such circumstances so our participation in the development work stopped. 

The methods and means for ecological diagnostics make rapid strides among all the NDT and TD developing areas. To provide the atmosphere monitoring recently the good results were achieved in the development of surface-acoustics wave sensors (SAW), laser measuring systems, infrared detectors and systems based on other physical principles. 

Before describing these methods, in the next paragraph we describe the measuring system. Magnetometer System... 

Figure 6 Sketch of sample from IN718 containing segregation, placed in measurement system.

The transfer efficiencies for ultrasonic nebulizers (USN) are about 20% at a sample uptake of about 1 ml/min. Almost 100% transfer efficiency can be attained at lower sample uptakes of about 5-20 pl/min. With ultrasonic nebulizers, carrier gas flows to the plasma flame can be lower than for pneumatic nebulizers because they transfer sample at a much higher rate. Furthermore, reduction in the carrier-gas flow means that the sample remains in the mass measurement system for a longer period of time which provides much better detection limits. 

E. O. Doebelin, Measurement Systems Application andDesign, McGraw-HiU Kogakusha, Ltd., Tokyo, 1975, p. 605. 

National Institute of Standards and Technology (NIST). The NIST is the source of many of the standards used in chemical and physical analyses in the United States and throughout the world. The standards prepared and distributed by the NIST are used to caUbrate measurement systems and to provide a central basis for uniformity and accuracy of measurement. At present, over 1200 Standard Reference Materials (SRMs) are available and are described by the NIST (15). Included are many steels, nonferrous alloys, high purity metals, primary standards for use in volumetric analysis, microchemical standards, clinical laboratory standards, biological material certified for trace elements, environmental standards, trace element standards, ion-activity standards (for pH and ion-selective electrodes), freezing and melting point standards, colorimetry standards, optical standards, radioactivity standards, particle-size standards, and density standards. Certificates are issued with the standard reference materials showing values for the parameters that have been determined. 

The principle of the Rockwed hardness test is that the depth of the indentation between a minor and a major load appHed through an indenter is inversely proportional to the hardness number. Using a minor load to set the indenter helps to reduce backlash in the measuring system. 

Sources of Error. pH electrodes are subject to fewer iaterfereaces and other types of error than most potentiometric ionic-activity sensors, ie, ion-selective electrodes (see Electro analytical techniques). However, pH electrodes must be used with an awareness of their particular response characteristics, as weU as the potential sources of error that may affect other components of the measurement system, especially the reference electrode. Several common causes of measurement problems are electrode iaterferences and/or fouling of the pH sensor, sample matrix effects, reference electrode iastabiHty, and improper caHbration of the measurement system (12). 

The Ravenfield model BS viscometer is a wide shear rate range iastmment with several possible measurement systems cone—plate, parallel plates, concentric cylinders, and taper plug. The last gives shear rates of up to 10 , and the cone—plate of up to 8 x lO". The viscosity range is... 

The following dynamics are commonly exhibited by measurement systems ... 

Where the manufacturer of the measurement device does not supply the associated eqiiipment (thermowells, sample conditioning equipment, and the like), the user must incorporate the characteristics of these components to obtain the dynamics of the measurement system. 

Similarly, it is often impossible, or at least very difficult, to experimentally determine the characteristics of a measurement system under the conditions where it is used. It is certainly possible to fill an emulsion polymerization reactor with water and determine the dynamic-characteristics of the temperature measurement system. However, it is not possible to determine these characteristics when the reactor is filled with the emulsion under polymerization conditions. 

Bubble-Tube Systems The commonly used bubble-tube system sharply reduces restrictions on the location of the measuring element. In order to ehminate or reduce variations in pressure drop due to the gas flow rate, a constant differential regulator is commonly employed to maintain a constant gas flow rate. Since the flow of gas through the bubble tube prevents entiy of the process liquid into the measuring system, this technique is particularly usefiil with corrosive or viscous liquids, liquids subjec t to freezing, and hquids containing entrained solids. 

Thermal Methods Level-measuring systems may be based on the difference in thermal characteristics oetween the fluids, such as temperature or thermal conductivity. A fixed-point level sensor based on the difference in thermal conductivity between two fluids consists of an electrically heated thermistor inserted into the vessel. The temperature of the thermistor and consequently its electrical resistance increase as the thermal conductivity of the fluid in which it is immersed decreases. Since the thermal conductivity of liquids is markedly higher than that of vapors, such a device can be used as a point level detector for liquid-vapor interface. 

The head developed in a compressor or pump is the energy force per unit mass. In the measuring systems it is often misnamed as (ft) while the units are really ft-lb/lbm or kilojoules. 

Stream scanning Brinkmann, Glimet, Goulter, Dantec, Erdco, Faley, Flowvision, Hiac/Royco, Kowa, Lasentec, Malvern, Met One, Particle Measuring Systems, Polytec, Procedyne, Rion, Spectrex 0.2-10,000 lm O.l-lOg (also on-line)... 

FMC Corporation, Material Handling Systems Division. To convert ciihic feet per hour to ciihic meters per hour, multiply hy 0.02832 to convert screw diameter in inches to the nearest screw size in centimeters, multiply hy 2.5. See elsewhere for conversion of particle sizes from one measurement system to another. 

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