5.1 This standard provides a method for testing the apparent sound insulating properties of doors in the field originally proposed by Morin (1).6 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.

5.3 Comparative measurements using this method and the method of Test Method E90 on the same door installations in a laboratory indicate good agreement between the transmission loss and normalized door insertion loss. See Appendix X1 and Ref (2).

5.4 The fixed-microphone and scanning methods have been compared in the field. See Appendix X2.

1.1 The sound insulation properties of a door are measured in a laboratory as the sound transmission loss in accordance with Test Method E90. Using those data 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 E336 actually 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 such cases 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 E336 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 should be expected.

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 and health practices and determine the applicability of regulatory limitations prior to use.