UL-1439:2011 pdf free download – STANDARD FOR SAFETY Tests for Sharpness of Edges on Equipment.
6 CalibratIon of Tester
6,1 The sharp edge tester shall be calibrated so that a 1-1/2 ±0.03 lbt (6.672 ±0.133 N) is present at the center of the head when the arm is between stops. The length of the arm is to be adustabIe for calibration purposes. See Figure 6.1 for a typical calibration procedure.
Exception: For special evaluations, when specified in the end-product standard, the torce may be adjusted to a different value.
6 1 revi$e Oicen,er 9. 2011
6.2 The adjustment set screws that hold the pivoted arm In place in the main drum are to be loosened.
6.3 With the handle securely held in a horizontal position, the calibration weight is to be attached to the center of the head.
6.4 The length of the arm within the main drum is to be adusted so that the weighted arm remains in a horizontal position with the calibration weight attached.
6.5 The adjustment setscrew(s) are to be tightened to securely lock the pivot arm in place within the main drum.
6.6 The calibration is to be rechecked and the weight removed.
7.2 Each tape is to be applied over approximately 180 degrees of the circumference of the test head to prevent stretching of the tape.
7.3 The tapes are not to be stretched when positioned on th€ head. See Figure 7.1
7.4 The center of the tape-covered head of the sharp-edge tester shall be positioned on the edge to be tested in the manner illustrated in Figure 7.2. The arm of the tester shall be between stops so that the tape-covered head exerts a 1-1/2 tI (6.7 N) on the edge. The tester shall be immediately moved along the edge a distance of 2 inches (50.8 mm) and then back to its starting position without removal of the tester from the edge. It shall then be withdrawn from the edge. The total distance of engagement between the edge and the tape-covered head is not to exceed 4 inches (101 mm). The time of travel is not to take longer than 5 seconds nor less than 2 seconds,
Exception: An edge less than 2 inches (50.8 mm) long shall be tested for a distance of twice its length. (Example: For an edge 1-1/2 inches or 41.2mm long, the tester Es to be moved along its length and back to the starting position so that the total distance of engagement between the edge and tester is 3 inches or 76.2 mm).
7.5 The tape-covered head shall be examined to determine whether or not penetration has occurred
through the two sensing layers. If penetration has occurred through the two sensing layers, the black indicating tape will be visible through the resulting cut.
8 Criterla
8.1 The application of the sharp-edge tester shown in Figure 5.1 or 5.2 to an accessible edge as
described in Sections 5- 7 shall not result in the cutting through of the two outer layers of the sensing tapes.
9 Report
9.1 The report is to include each of the fllwing items:
a) ldentification of the equipment tested, including the manufacturer’s identity, class of product, and the model designation.
b) ldentification of each edge tested by description of its location.
c) Record of the observation related to penetration of the sensing tapes. (Example: Acceptable
or unacceptable.)
d) Date of Test.