• ASTM E2479-11

ASTM E2479-11

Standard Practice for Measuring the Ultrasonic Velocity in Polyethylene Tank Walls Using Lateral Longitudinal (LCR) Waves

ASTM International, 07/01/2011

Publisher: ASTM

File Format: PDF

$29.00$58.00


Published:01/07/2011

Pages:7

File Size:1 file , 330 KB

Note:This product is unavailable in Russia, Ukraine, Belarus

1.1 This practice covers a procedure for measuring the ultrasonic velocities in the outer wall of polyethylene storage tanks. An angle beam lateral longitudinal (LCR) wave is excited with wedges along a circumferential chord of the tank wall. A digital ultrasonic flaw detector is used with sending-receiving search units in through transmission mode. The observed velocity is temperature corrected and compared to the expected velocity for a new, unexposed sample of material which is the same as the material being evaluated. The difference between the observed and temperature corrected velocities determines the degree of UV exposure of the tank.

1.2 The practice is intended for application to the outer surfaces of the wall of polyethylene tanks. Degradation typically occurs in an outer layer approximately 3.2-mm (0.125-in.) thick. Since the technique does not interrogate the inside wall of the tank, wall thickness is not a consideration other than to be aware of possible guided (Lamb) wave effects or reflections off of the inner tank wall. No special surface preparation is necessary beyond wiping the area with a clean rag. Inside wall properties are not important since the longitudinal wave does not strike this surface. The excitation of Lamb waves must be avoided by choosing an excitation frequency such that the ratio of wavelength to wall thickness is one fifth or less.

1.3 UV degradation on the outer surface causes a stiffening of the material and an increase in Young's modulus and the longitudinal wave velocity.

1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

More ASTM standard pdf

ASTM D5194-96(2000)

ASTM D5194-96(2000)

Standard Test Method for Trace Chloride in Liquid Aromatic Hydrocarbons

$26.00 $52.00

ASTM F1118-91(1997)e1

ASTM F1118-91(1997)e1

Standard Specification for National Air Medical Transport Units Resources Catalog

$25.00 $50.00

ASTM F428-83(1997)e2

ASTM F428-83(1997)e2

Standard Test Method for Intensity of Scratches on Aerospace Glass Enclosures

$25.00 $50.00

ASTM D6170-97e1

ASTM D6170-97e1

Standard Guide for Selecting a Ground-Water Modeling Code

$32.00 $65.00