Penetrometer method

De Man (1983) has reviewed this property of fats. Consistency is defined as (1) an ill-defined and subjectively assessable characteristic of a material that depends on the complex stress-flow relation or as (2) the property by which a material resists change of shape. Spreadabil-ity, a term used in relation to consistency, is the force required to spread the fat with a knife. The definition is similar to that for hardness the resistance of the surface of a body to deformation. The most widely used simple compression test in North America is the cone penetrometer method (AOCS Method Cc 16-60, 1960). More sophisticated rheological procedures are also available. Efforts have been made to calibrate instrumental tests with sensory response. With the cone penetrometer method, penetration depth is used as a measure of firmness. Hayakawa and De Man (1982) studied the hardness of fractions obtained by crystallization of milk fat. Hardness values obtained with a constant speed penetrometer reflected trends in their TG composition and solid fat content. 

One possible reason suggested by Flory and Mandelkern (1956) for or contribution to the discrepancies indicated in Table 2 is the inability of the penetrometer method to detect the maximum temperature of melting because of its relative insensitivity and because of the upper "tail to the crystallinity-temperature curve as deduced from the copolymer crystallinity theory of Flory (1955). Dole and Wunderlich (1957, 1959) found, however, that two melting regions each of the quenched 80/20 and 60/40 copolymers could be observed in the calorimetric experiments. The specific heat curves of these two copolyesters are illustrated in... 

In recent times, investigations utilizing penetrometer methods have received considerable attention in virtually all areas of the world. Interest has been generated by developing awareness that direct relationships between penetrometer results and foundation design have been formulated. 

Penetrometers are easy to use giving good results and correlating well with the sensory assessment of gels etc. Nevertheless these instruments yield a purely empirical method working on the principal of linear compression, penetration or back extrusion. 

The stability of foams is usually measured by the volume of liquid drained from a foam during a specific time at room temperature (10. 15. 17) or by a decrease in foam volume over time. Methods employed to measure foam stability include the rate of fall of a perforated weight through a column of foam (20. 22), the penetration of a penetrometer cone (17), or the ability to support a series of specific weights (277. 

The lower limit of the elastic range, the glass transition temperature, can be easily determined by refractometric, volumetric, or other well known methods. The upper limit suffers from an exact definition the transition from the fixed liquid to the liquid state occurs without transformation. But as the viscosity decreases exponentially with the temperature it is very convenient to define a 1 flow-temperature by penetrometer measurements. If the rate of temperature rise is kept constant, this temperature is reproducible within 1° or 2°C. The penetrometer indicates a temperature where macroscopically one would call the substance liquid. ... 

Puncture probes are commonly used for fruits and vegetables, and allow for the determination of force at rupture of the cellular structure. The procedure outlined below is adapted from the method of Bourne (1979). Cone penetrometers are commonly employed for determining firmness and yield value for foods such as margarine and butter, which may be a reflection of the product s spreadability. Quite often it is desirable to use a testing system that provides a constant deformation rate. Additionally, a mechanical testing machine allows for production of a force/deformation curve to further analyze the data. 

The solid-like properties may be measured by non-destructive dynamic rheology analysis or by destructive methods using a Penetrometer, Jelly Tester, Instron instruments, or other types of texture analyzers. The latter methods are the most useful due to their simplicity and speed. Texture analysis of whippable emulsion must always be compared with the amount of air incorporated into the foam, which is known as percentage overrun and is calculated as follows ... 

Penetrometers come in a variety of types. One of the most widely used is the Precision penetrometer, which is used for measuring consistency of fats. The procedure and cone dimensions are standardized and described in the Official and Tentative Methods of the American Oil Chemists Society. According to this method, the results are expressed in mm/10 of penetration depth. Haighton (1959) proposed the following formula for the conversion of depth of penetration into yield value ... 

Consistency of fats is commonly determined with the cone penetrometer, as specified in the Official and Tentative Methods of the American Oil Chemists Society (Method Cc 16-60). Other methods that have frequently been employed involve extrusion they include the extrusion attachment to the shear press (Vasic and deMan 1967), an extrusion rheometer used with the Instron universal testing machine (Scherr and Witt-nauer 1967), and the FIRA-NIRD extruder (Prentice 1954). 

By any appropriate conventional viscosimeter, or by AOCS Bubble Time Method Tq 1A-64, assuming density to be unity. Fluid lecithin having a viscosity less than 7,500 centipoises may be considered a premium grade. Using Precision cone 73525, Penetrometer 73510 sample conditioned 24 hours at 25°C. 

In addition to the torsion plastograph mentioned above, a number of other methods are used for appraising the properties of plastic bodies in practice. Plastic strength (rigidity) is determined by means of the Rebinder penetrometer which measures the depth of penetration of a cone forced into the body under constant load. The respective quantity is related to yield point. The commercial Brabender plastograph measures the resistance of mixture to kneading. The extrusion viscometer, from which the material is extruded under pressure, is analogous to flow-out viscometers. 

The measurement of the needle penetration of petroleum wax (ASTM D1321, IP 376) gives an indication of the hardness or consistency of wax. This method uses a penetrometer applying a load of 100 g for 5 s to a standard needle with a truncated cone tip. The sample is heated to 17°C (30°F) above its congealing point, poured into a small brass cylinder, cooled, and placed in a water bath at the test temperature for 1 h. The sample is then positioned under the penetrometer needle, which when released penetrates into the sample. The depth of penetration in tenths of millimeters is reported as the test value. This method is not applicable to oUy materials or petrolatum, which have penetrations greater than 250. 

PENETRATION-INDUCED PORE PRESSURE MAGNITUDES - METHODS TO DETERMINE TRANSPORT PARAMETERS FROM TERRESTRIAL AND MARINE PENETROMETER TESTING... 

Lee, D.S. Elsworth, D. 2003. Indentation of a free-falling sharp penetrometer into a poroelastic seabed, (under review). International Journal for Numerical and Analytical Methods in Geomechanics. 

Simple hand-operated penetrometers suitable for measuring the plasticity of bodies to be extruded and for extruded columns are on the market. By using the penetrometer, designed to determine the plasticity, the resistance caused by penetration over the cross section of the extruded sample is established. It is advisable to use a template in order to ensure that the penetration depth is always measured at the same spot. This is a well-proven method for application on large surface cross sections, on slugs or immediately after extruder pressure heads, as used in brick factories, but is unsu-... 

It is a fact that even today no methods exist, which clearly establish and depict the plasticity relevant to extrusion. This holds true particularly for such methods as Pfefferkorn or the penetrometer, which provide a reference figure. It appears that the most apt are those methods that simulate the extrusion process. 

The plasticity readings obtained from the Brabender measuring kneader expressed in the form of torque figixres are not identical with the plasticity figures relevant to extrusion. This also holds true for those measured values determined by the penetrometer or other measuring methods. Yet the Brabender measuring kneader is ideally suited for the development or optimisation of bodies which need to be plastified prior to extrusion by means of continuous or intermittent kneading. 

The CPT was originally known as the Dutch CPT. The test is a versatile sounding method that can be used to determine the stratigraphic identification, soil strength, deformation, and dynamic properties of sediments. In recent years, this has been expanded to include chemical data and hydraulic properties of the subsurface strata. The current cone penetrometer has its beginnings in the early 1930s in the Netherlands. Cone penetrometers... 

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