You’re writing an NBS Specification for glazed partitioning and your acoustician has advised you to select a product that achieves a particular acoustic sound insulation. A product manufacturer has offered you an acoustic test ‘certificate’, but how do you know it is credible? Optima’s Technical Manager, Peter Long, sets out the questions you should ask before you accept it. Q1. Does the test apply to a properly dimensioned partition? Firstly, it is important to make sure that the test certificate states the test sample size. Glass partitions are full height structures and would normally comprise several panes of glass, so it is not acceptable to test partitions as ‘windows’ or ‘glazing’ in smaller sized openings. Testing samples using these methods will generally give an artificially higher acoustic rating result than testing a representative partition sample with multiple modules of glass, glazing joints and perimeter track-work. Such a result cannot therefore be directly compared to a full partition sample test result. Q2. Was the test carried out in an accredited laboratory? Secondly, for the acoustic rating value to be credible, it must have been obtained in an accredited laboratory. For direct comparisons to be made between one system and another, they must both have been laboratory tested in accordance with the correct sample definition in EN ISO 10140-1, by a UKAS accredited laboratory. UKAS is the United Kingdom Accreditation Service and all Optima acoustic testing is carried out in UKAS accredited laboratories. Q3. Was the acoustic rating data produced using modelling software? Lastly, it is not acceptable to use software modelled performance values in comparison to laboratory tested outcomes. These methods have a high margin of error and are designed to give a guide to potential performance and not proof of actual performance. Assessments of Rw values should therefore be treated with great caution. Summary – Acoustic Rating Certificate Checklist Make sure your acoustic rating test certificate has the current information • Has the product been tested in a laboratory? • Where was it tested? • How big was the sample and how was it configured? • Is there unequivocal evidence of the test? More Information If you’d like to know more about acoustic effectiveness of glass partitions, we invite you to read the following blogs: • An Essential Tip for Specifiers When Comparing Acoustic Glass Partitions • Expert Opinion: Acoustic Privacy Get in touch if you’d like us to advise you on Optima Acoustic Partitioning.