Dynamic pressure measurement

Strain-gauge pressure transducers are manufactured in many forms for measuring gauge, absolute, and differential pressures and vacuum. Full-scale ranges from 25.4 mm of water to 10,134 MPa are available. Strain gauges bonded direc tly to a diaphragm pressure-sensitive element usually have an extremely fast response time and are suitable for high-frequency dynamic-pressure measurements. 

Scanning electron microscopic examination of pure, dextrinated and RD 1333 LA) 10) L. Avrami N. Palmer, Impact Sensitivity of Lead Azide in Various Liquids with Different Degrees of Confinement , PATR 3965 (1969) 11) M.F. Zimmer L.D. Lyston, Dynamic Pressure Measurements on Small Amounts of Detonating Lead Azide , Explosivst 18, No 1, 12-15 (Jan 1970) 12) R.W. Hutchinson,... 

PQ) M.F, Zimmer L.D. Lipton, "Dynamic Pressure Measurements on Small Amounts of Detonating Lead Azide", Explosivstoffe 18, 12—15(1970). Abstracted in Expls Pyrots 3(8), 1970. (To evaluate the safery of handling small (few mg to 1 g) amts of LA in daily pilot plant operations, dynamic pressure measurements were taken with/or without protective cloth. The distance from the sample to die gauge was changed from 1 to 30cm)... 

Cavity Type Transducer suitable for making dynamic pressure measurements of ordnance items was discussed by C.L.Pataky, PATR 232"1(1956)(U)... 

M.F. Zimmer L.D. Lyston, Dynamic Pressure Measurements on Small Amounts of Detonating Lead Azide , Explosivst 18, No 1, 12—15 (Jan 1970) 12) R,W. Hutchinson,... 

In today s microfluidic technology, not many applications require dynamic pressure measurement. A pressure measurement technique with a good dynamic would extend the boundaries of microfluidics technology. 

Dynamic pressure may be measured by use of a pitot tube that is a simple impact tube. These tubes measure the pressure at a point where the velocity of the fluid is brought to zero. Pitot tubes must be parallel to the flow. The pitot tube is sensitive to yaw or angle attack. In general angles of attack over 10° should be avoided. In cases where the flow direction is unknown, it is recommended to use a Kiel probe. Figure 10-3 shows a Kiel probe. This probe will read accurately to an angle of about 22° with the flow. 

Chile [Prog. Aerosp. Sc7, 16, 147-223 (1975)] reviews the use of the pitot tube and allied pressure probes for impact pressure, static pressure, dynamic pressure, flow direction and local velocity, sldn friction, and flow measurements. 

Nellis, W.J., Properties of Condensed Matter at Ultrahigh Dynamic Pressures, in High Pressure Measurement Techniques (edited by Peggs, G.N.), Applied Science, London, 1983, pp. 69-89. 

Tackifying resins enhance the adhesion of non-polar elastomers by improving wettability, increasing polarity and altering the viscoelastic properties. Dahlquist [31 ] established the first evidence of the modification of the viscoelastic properties of an elastomer by adding resins, and demonstrated that the performance of pressure-sensitive adhesives was related to the creep compliance. Later, Aubrey and Sherriff [32] demonstrated that a relationship between peel strength and viscoelasticity in natural rubber-low molecular resins blends existed. Class and Chu [33] used the dynamic mechanical measurements to demonstrate that compatible resins with an elastomer produced a decrease in the elastic modulus at room temperature and an increase in the tan <5 peak (which indicated the glass transition temperature of the resin-elastomer blend). Resins which are incompatible with an elastomer caused an increase in the elastic modulus at room temperature and showed two distinct maxima in the tan <5 curve. 

Equation (22) has been confirmed by a variety of techniques including neutron scattering, dynamic light scattering, and osmotic pressured measurements [23]. As concentration increases the concentration blob decreases in size until the Kuhn length is reached and the coil displays concentrated or melt Gaussian structure. The coil accommodates concentrations between the overlap and concentrated through adjustment of the concentration blob size. 

Bisphthalonitrile monomers were cured neat, with nucleophilic and redox co-reactants, or in combination with a reactive diluent. Dynamic mechanical measurements on the resulting polymers from -150 to +300°C turn up several differences attributable to differences in network structure. Rheovibron results were supplemented with solvent extraction, differential scanning calorimetry (DSC), vapor pressure osmometry, and infrared spectroscopy to characterize the state of cure. 

The experimental techniques for the study of conformational branched properties in solution are the same as used for linear chains. These are, in particular, static and dynamic light scattering, small angle X-ray (SAXS) and small angle neutron (SANS) scattering methods, and common capillary viscometry. These methods are supported by osmotic pressure measurements and, nowadays extensively applied, size exclusion chromatography (SEC) in on-line combination with several detectors. These measurements result in a list of molecular parameters which are given in Table 1. 

The dynamic storage modulus of closed-cell PE foams was investigated by dynamic viscoelastic measurement in the compression mode. It was found that dynamic modulus correlated with compression hardness and that the resistance against pressure inside the cells had no effect upon static modulus or dynamic storage modulus. 8 refs. 

The pressures measured in vacuum technology today cover a range from 1013 mbar to 10 mbar, i.e. over 15 orders of magnitude. The enormous dynamics involved here can be shown through an analogy analysis of vacuum pressure measurement and length measurement, as depicted in Table 3.1. 

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