Sound Insulation of Road Traffic Noise Reducing Devices
Testing the Acoustic Performance of Road Traffic Noise Reducing Devices to BS EN 1793-1:2012, 2017 and BS EN 1793-2:2012.
BS EN 1793-1:2012, BS EN 1793-1:2017: Intrinsic characteristics of sound absorption
BS EN 1793-1 is concerned with measuring the absorptive properties of road traffic noise reducing devices. It is important that the sample is assembled in the same manner as the manufactured device including posts, brackets, connections and seals between component parts. At least one post is included in the sample for testing and the length of the panels on one side of the post shall be greater than or equal to 2 m. The sample is assembled on the floor of the reverberation room with the side facing the traffic facing the inside of the room. This method can also be used to test surface cladding for tunnel walls etc. When installed the test method is very similar to that used to measure absorption in the large reverberation room. The results are calculated and presented in a slightly different manner, however.
BS EN 1793-2:2012: Intrinsic characteristics of airborne sound insulation
BS EN 1793-2 is concerned with measuring the sound insulation properties of road traffic noise reducing devices. We advise that the barrier should be built to fill the aperture (this is the cheapest option of testing the device), if this cannot be achieved then the plinth should be bricked up to lift the barrier to fill the remaining gap. It is important that the sample is assembled in the same manner as the manufactured device including posts, brackets, connections and seals between component parts, edge supports must not overlap the sample by more than 70 mm. At least one post is included in the sample for testing and the length of the panels on one side of the post shall be greater than or equal to 2 m. The side facing the traffic faces the source room. When installed the test method is very similar to that used to measure sound insulation in the transmission suite. The results are calculated and presented in a slightly different manner, however.
What is expected of you?
Drawings and written descriptions of the samples must be provided prior to testing (preferably prior to quotation); a test report cannot be provided without this information. We expect that your company will assemble the sample for testing to ensure the wall is constructed in the usual manner. Providing all the usual building materials for construction and organising and paying for all transportation costs for these materials as required. The specimen should be assembled using the highest quality of components and labour. In the case of BS EN 1793 part 2 testing the smallest of leaks can greatly reduce the measured sound insulation index. A reflective frame is also required to surround the sample so that sound cannot enter from the sides.
FAQs
What size of sample should I provide?
For BS EN 1793 part 1 testing a 12m2 sample the ratio of the dimensions is important; a 3m × 4m sample is adequate to fulfil the requirements of the standard. The aperture size is 2.80m × 3.62m and for BS EN 1793 part 2 testing you should expect to fill this for the test.
What do our customers most often forget when preparing for testing at the laboratory?
If the product uses posts in a real construction then the test specimen must also have a post (both 1793-1 and 1793-2 tests).
Sample will need to be installed on a bed of sand (provided) to ensure that there are no cavities beneath the sample. The reflective frame (supplied by the client) needs to cover that too.
How long is each test?
For BS EN 1793 part 1 testing the first test is always the longest because empty room reverberation times need to be measured prior to testing. After calibration the first test should take 20-30mins and subsequent tests should take 15-20mins.
For BS EN 1793 part 2 testing the longest part of each test is always the build process. When it comes to the acoustic tests the first sound insulation test is the longest because we need to measure the reverberation times in the receiver room, after this provided the material of the partition wall doesn’t change subsequent sound insulation tests are shorter. After calibration the first test will take 20-30mins and subsequent tests which don’t need reverberation times should take 15-20mins each.
How many tests can I do in a day?
Provided the installation of the sample doesn’t hold us up too much we should be able to do up to four tests in a day. If necessary, we can do more than this for an additional charge.
When will I get the report? When can I get the results?
We can provide preliminary results on the day of test. The test report will follow in 2-4 weeks after test completion, depending on our workload and the complexity of the test carried out.
Danny Wong-McSweeney
Test Lab Manager
t: +44 (0)161 295 2807 // 07811 779 343
e: d.b.c.wong-mcsweeney@salford.ac.uk