Standard depth of penetration

A phenomenon known as the skin effect is u.sed to describe the depth of penetration of the eddy currents, which is proportional to the current frequency (/ in Hz), the electrical conductivity (rr in mhos.m) and the magnetic permeability (n in H/m) of the material tested. The standard depth of penetration (cl in m) can be calculated using the formula... 

SDP standard depth of penetration SLS static light scattering... 

Depth of penetration Rockwell superficial and Rockwell standard hardness tests... 

The manufactured 90 mm x 90 mm x 10 mm three-layered B4C/B4C-30wt%SiC tiles were tested as armor [67], The photographs of the experiment set-up of the ballistic test as well as a residual impression in the clay box that was used as one of the criteria in the ballistic performance of laminates are shown in Fig. 7.17. The ballistic penetration tests were performed to evaluate the ballistic performance of the laminates. Depth of penetration tests were used to evaluate the ballistic performance of the composite laminates. In addition, pure B4C monolithic ceramics were used as a standard for the test. Test panels were made using the three-layered B4C/B4C-SiC laminate and B4C monolithic ceramic material as the hard face. While the B4C monolithic tile had 100% of its theoretical density, the three-layered B4C/B4C-30wt%SiC laminates had about 3-4% of porosity. A commonly used Spectra fiber-reinforced polymer composite was used as backing plates. The targets were mounted on clay and the projectile was shot at the target at a specific velocity. 

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 ... 

Standard skin preparation increases the depth of penetration of Jessner s solution and improves the results - at the same time as increasing the risk of complications. An allergy test is essential, especially because of the resorcinol in the formula. 

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. 

The device has a very basic construction and can be easily used. It uses a standard 8 kg rammer (4.6 kg optional for weaker materials) dropping through a height of 575 mm and a steel drive rod with a replaceable point or disposable 60° cone tip. During the test, the depth of penetration is recorded every time the load is applied and results are expressed in millimetres per blow, known as the DCP index or rate. 

Apparatus for measuring the consistency of lubricating grease, asphalt and rubbers. A standard cone (for grease) or needle (for wax, rubber or asphalt) is lowered onto a test sample, under prescribed conditions, and the depth of penetration is measured. 

Vicat Needle. An instrument for evaluating the consistency of cement in terms of the depth of penetration of a needle of standard shape and under a standard load it was designed by L. J. Vicat, a Frenchman, in the early 19th century. Details of dimensions and... 

Penetration. Penetration is an indicator of a grease s relative hardness or softness and not a criterion of quality. Measured on a penetrometer at 77°F (25°C), it is the depth of penetration (in tenths of mihimeters) into the grease of a standard 150-g cone. The softer the grease, the greater the penetration number will be. 

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