Views:98 Author:Site Editor Publish Time: 2018-06-29 Origin:Site
The panel shall be pre-loaded to the test load. A pre-load of 50 lbs/ft² (i.e. 200 lb In the case of a panel that is 4 ft² - 2' x 2') shall then be applied and the instrumentation measuring deflection and load shall be set at zero. (Reference zero = 50 lbs/ft² pre-load)
After the pre-load, the panel shall be tested by increments not exceeding 50 lbs/ft², with initial load no more than one-half test load. Rate of load application shall not exceed 375 lbs/ft² per minute.
Deflection and permanent set shall be measured at the panel's center, midspan of edge, and "weakest point" as defined by the manufacturer and verified by the independent test agency.
Note: For products with uneven bottom surfaces and where the deflection and set are measured on the bottom of the panel, the measurements shall be taken at the lowest adjacent horizontal surface.
Loads shall be applied for a minimum of one (1) minute and deflection readings taken at the end of the period. The load shall then be relaxed to reference zero (Reference zero = 50 lbs/ft² pre-load) for a minimum one (1) minute and deflection shall be recorded.