Significance and Use
5.1 This standard provides a method for testing the apparent sound insulating properties of doors in the field originally proposed by Morin (. ) This allows doors to be evaluated with a result that has been found to be similar to the transmission loss.
5.2 The results of this measurement are the normalized door insertion loss, NDIL, at individual frequencies, and the single-number rating door transmission class, DTC. The insertion loss is normalized by the small change in sound level which occurs on the source side when the door is opened and closed. The results are in theory the same when measured in each direction through the door, but differences have been observed in practice.
5.3 Comparative measurements using this method and the method of Test Method on the same door installations in a laboratory indicate good agreement between the transmission loss and normalized door insertion loss when the door is in a wall between two rooms and flanking is not significant. No similar verification has been done for corridors. See and Ref (. )
5.4 The fixed-microphone and scanning methods have been compared in the field. See .
1.1 The sound insulation properties of a door are measured in a laboratory as the sound transmission loss in accordance with Test Method . Using those data, the single-number rating sound transmission class (STC) is assigned. In the field, the rooms on one or both sides of a partition containing a door are often either too small or too large and absorptive to allow the apparent transmission loss (ATL) of the partition-door assembly to be measured. Even if that is not the case, the result measured is the composite ATL of the partition including the door, and not that of the door itself. Test Method states that it is impossible to measure the ATL of a portion of a partition such as a door according to the procedures of that standard. This test method provides a method of evaluating doors in the field using a normalized insertion loss with a resulting single-number rating door transmission class, DTC. This method is intended primarily for hinged personnel doors with latching mechanisms and is limited to door openings of area less than 6 m2. The flanking effects of surrounding structure are reduced compared to Test Method but not completely eliminated. In a laboratory environment, the DTC is close to or equal to the STC of the door, but in the field results less than the laboratory STC are to be expected due to flanking.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 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.
1.4 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.