BHMA A156-21:2006 pdf download.AMERICAN NATIONAL STANDARD FOR THRESHOLDS
4.1.1 Test Fixture Provide a loading device having a flat bed large enough to accept a threshold test specimen and that will not deflect when the specified load is applied. The load shall be measured with a dial or digital gage having a combined calibration and reading accuracy within 2%. All threshold measurements are to be taken with a gage accurate within±.001 in.(.025mm). Use a 1/4 in. (6.3 mm) thick cold rolled steel plate 3/4 in. (19 mm) wide and 3 in. (76mm) long connected to a 3/4 in. (19 mm) diameter steel rod with a maximum length of 6 in.(152mm) for transferring the load to the threshold surface. The fixture shown in the Figure below shall be used to apply the load to the specimen surface, and with support on one side only to prevent the specimen from sliding. The swivel mount is intended to maintain full plate contact on sloping thresholds
4.1.2 Procedure Place a 12 in. (305mm) long threshold specimen on the flat bed. The before and after measurements shall be taken at the same position. This single position shall be at the center of the length of the specimen and at the center of the widest span between two adjacent support points, including those which contact the bed under load. Orient the steel plate centered with the 3 in. (76mm) dimension in the direction of the threshold length. Gradually apply a downward compressive load within 20 seconds±5 seconds until a reading of 1000 lbf (4448 N) is reached. After 15 minutes ±30 seconds at the specified load, remove the load and remeasure the height of the specimen. Permanent set shall not exceed 0.040 in. (1 .02mm).
5.TYPES
5.1 When using any of the following type numbers, the finish, height, width, length and screw fasteners required shall be specified in addition to the following type numbers. Consult individual manufacturer' s catalogs for availability. If the threshold is to be used with a vertical rod exit device, it shall also be specified if the threshold is to act as the latch holder.
5.2 The illustrations shown are typical and are not requirements for product design.
5.3 The design and type of thresholds are not limited by the following examples. Thresholds not shown are described using the numbering system provided. Refer to manufacturers catalogs so as to not to devise a number describing a product that does not exist.BHMA A156-21 pdf download.