【国外标准】 Standard Practice for Laser Technologies for Direct Measurement of Cross Sectional Shape of Pipeline and Conduit by Rotating Laser Diodes and CCTV Camera System

4.1 Laser profiling assessment is a quality control tool for identifying and quantifying deformation, physical damage, and other pipe anomalies after installation, providing means and methods for determining the quality of workmanship and compliance with project specifications. Laser profiling capabilities include:4.1.1 Measurement of the structural shape, cross sectional area and defects;4.1.2 Collection of data needed for pipe rehabilitation or replacement design; and4.1.3 Post rehabilitation, replacement or new construction workmanship verification.4.2 A laser profile pre-acceptance and condition assessment survey provides significant information in a clear and concise manner, including but not limited to graphs and still frame digital images of pipe condition prior to acceptance, thereby providing objective data on the installed quality and percentage ovality, or degree of deformation, deflection or deviation, that is often not possible from an inspection by either a mandrel or only CCTV.1.1 This practice covers the procedure for the post installation verification and acceptance of buried pipe deformation using a visible rotating laser light diode(s), a pipeline and conduit inspection analog or digital CCTV camera system and image processing software. The combination CCTV pipe inspection system, with cable distance counter or onboard distance encoder, rotating laser light diode(s) and ovality measurement software shall be used to perform a pipe measurement and ovality confirmation survey, of new or existing pipelines and conduits as directed by the responsible contracting authority. This standard practice provides minimum requirements on means and methods for laser profiling to meet the needs of engineers, contractors, owners, regulatory agencies, and financing institutions.1.2 This practice applies to all types of material, all types of construction, or shape.1.3 This practice applies to gravity flow storm sewers, drains, sanitary sewers, and combined sewers with diameters from 6 in. to 72 in. (150 mm to 1800 mm).1.4 The Laser Light Diode(s) shall be tested, labeled and certified to conform to US requirements for CDRH Class 2 or below (not considered to be hazardous) laser products or certified to conform to EU requirements for Class 2M or below laser products as per IEC 60825-1, or both.1.5 The profiling process may require physical access to lines, entry manholes and operations along roadways that may include safety hazards.1.6 This practice includes inspection requirements for determining pipeline and conduit ovality only and does not include all the required components of a complete inspection. The user of this practice should consider additional items outside this practice for inspection such as joint gap measurement, soil/water infiltration, crack and hole measurement, surface damage evaluation, evaluation of any pipeline repairs, and corrosion evaluation.1.7 This standard practice does not address limitations in accuracy due to improper lighting, dust, humidity, fog, moisture on pipe walls or horizontal/vertical offsets. Care should be taken to limit environmental factors in the pipeline that affect accuracy of the inspection.1.8 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.9 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. There are no safety hazards specifically, however, associated with the use of the laser profiler specified (listed and labeled as specified in 1.3).1.10 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.