The results and uses of a New Interlaboratory Study for ASTM E90 for frequently constructed wall types

How does one compare test reports from two different labs? How do we improve our standard test methods? How does a lab prove they get the same results over time? Every ASTM standard method is required to include a precision and bias statement. The precision statement is based on interlaboratory studies where multiple labs do repeated tests on the same sample. That data was only relevant when it is similar to the type of sample usually tested. The last interlaboratory study to establish the precision for ASTM E90 was completed over 20 years ago on low-STC steel panels. This presentation covers the initial results of a new study that included over 80% of North American accredited labs using higher-performing, commonly used, steel stud wall assemblies. The authors will present the uncertainty determined by the study along with sources of variation between the labs including opening size, microphone type, and room volumes. The presentation will also discuss how consultants can use this information to better evaluate laboratory test data, and the industry as a whole can use it to improve the reliability of acoustic testing.