ASTM F2055-17(R2021) pdf free download

ASTM F2055-17(R2021) pdf free download.Standard Test Method for Size and Squareness of Resilient Floor Tile by Dial Gauge Method
4. Apparatus
4.1 The apparatus shall consist of four dial gauges and two reference index strips mounted on a flat bedplate in a configu- ration that, by rotation of the sample, allows the measurement of all four sides of resilient tile samples (see Fig. 1). One edge of the bedplate is elevated to create a test surface which is offset or tilted 15 6 1 degrees from horizontal. This offset applies minimal pressure to the test specimen against the longer index strip to ensure repeatable measurement. A refer- ence plate representing target tile size and squareness is used to zero all dial gauges (see Fig. 2). 4.2 Dial Gauges—The four dial gauges are mounted in guide slots that are machined into the bedplate to allow for measurement of various tile sizes while remaining within 10% ofthe corner ofthe tile edge (for the two corner gauges and one squareness gauge) or within the central 10 % of the tile edge (for the center gauge only). Dial gauges may report measure- ments using either electrical or mechanical means, but they shall be graduated to read 0.001 in. (0.02 mm) and have a stem travel greater than 0.25 in. (6 mm). The contact foot of the dial-gauge stem shall be flat 0.50–0.75 6 0.001 in. (12.7–19.1 mm 6 0.2 mm) in diameter and exert a total force of not more than 3.0 6 0.1 ozf (0.83 6 0.003 N). Dial gauges shall be securely positioned so that when the reference plate is in place, the contact foot is extended approximately 50% of its full travel.4.3 Index Strips—The apparatus contains 2 fixed index strips. A horizontal index strip shall be mounted parallel to and just inside the lower edge of the bedplate. It shall be 1.5 6 0.1 in. (38 6 3 mm) greater in length and a minimum of twice the thickness of the largest tile to be tested. A second index strip shall be mounted 90° 6 10 s (1.57080 6 0.00005 rad.) to the horizontal index strip. The lower end ofthis index strip shall be 0.125 6 0.01 in. (3.1 6 0.25 mm) above the right end of the horizontal index strip and is used to locate one corner of the sample tile. 4.4 Reference Plate—The reference plate shall be made to the target dimensions of the manufactured tile. The length and width dimensions shall be within 6 0.001 in. (0.02 mm) of the specified dimensions of the resilient tile. The reference plate shall contain at least two sides which are perpendicular to 90° 6 10 s (1.57080 6 0.00005 rad.) to one another and are used to set the squareness gauge to zero.
6. Conditioning
6.1 Condition the test specimens, reference plate, and appa- ratus a minimum of 24 h at 73.4 6 1.8 °F (23 6 1 °C) and 50 6 10 % relative humidity. Tests shall be conducted in this same environment. Samples shall be conditioned on a flat surface such as a table or floor surface to ensure they will contact the bedplate uniformly during measurement.
7. Procedure
7.1 Place the appropriate reference plate onto the bedplate surface and slide it firmly against the two index strips. Set each of the four dial indicators to zero. Remove the reference plate. All dial indicators will now reflect their fully extended mea- surements. In the case ofdigital dial indicators, the display will indicate a negative number. In the case of mechanical dial indicators, the display will move counter-clockwise from zero. N OTE 1—Dirt and foreign particles may collect along the upper face of the index strip and affect the zero setpoint. Use a small brush to maintain the cleanliness of the index strip surfaces before and after each use. 7.2 Measuring Size and Squareness—Identify one edge of the sample tile as “Edge #1” by attaching a label to the face of the tile near that edge. Place the tile into the apparatus and carefully move it into position such that it will depress all four dial gauges and is in firm contact with both index strips. Record the measurements on all four gauges to the nearest 0.001 in. (0.02 mm). 7.3 Remove the tile from the bedplate and rotate it 90° in the clockwise direction. Repeat the process described in 7.2 and record the four gauge readings. Repeat for each of the two remaining sides. 7.4 After all samples have been measured, place the refer- ence gauge back on the bedplate to verify that no movement of dial gauges has occurred. A movement ofgreater than 0.001 in. (0.02 mm) shall be cause to repeat the measurement process.