Laboratory testing is the common element which all participants in the construction process utilize to provide assurance that their part of the process is correct. Testing of materials, products and methods of construction is performed at every stage of the job. How do you select a laboratory that performs tests correctly and produces reliable data? One way is through experience, based on trial and error; another is to perform an independent evaluation of a laboratory. Either could be very costly in terms of dollars and time--and you still might not be sure that the laboratory provides adequate results. Another approach is to use a laboratory which has been evaluated by an independent third party.
The National Voluntary Laboratory Accreditation Program (NVLAP) has been evaluating testing laboratories since 1979. The program, operated by the National Bureau of Standards (NBS), is totally independent of both the laboratory and potential users of laboratory services. When an applicant laboratory successfully meets all evaluation criteria it is granted accreditation by NBS. The NVLAP evaluation of a laboratory involves two basic elements: (1) an on-site assessment of the facilities, and (2) the laboratory's participation in an on-going proficiency testing program.