ITF

45 6. EVENNESS (ITF CS 02/02) The court surface should be free from any imperfection that causes an inconsistent ball bounce, allows the collection of water, or significantly increases the risk of injury to players. Undulations in the court are measured relative to a rigid straight edge placed on the surface. Apparatus Test apparatus consists of: 3 m straight edge, made from box-section aluminium or equivalent. Wedge approximately 25 mm wide and 200 mm long, with marked height increments of 1 mm. Two supports for the straight edge, of equal height. Calibration of apparatus Devices used for evenness measurements should be calibrated annually for straightness of the edge against a known standard to ± 0.5 mm. Surveying-quality straight edges in serviceable condition are deemed appropriate. The straight edge can be checked by hanging a plumb line against the bottom edge. The wedge increments and supports can be measured using a calliper, calibrated against a known standard to ± 0.25 mm. Check for any damage to the straight edge and wedge prior to testing. Test procedure 1. Lay the straight edge on the surface, parallel to the net, and look for deviations that warrant measurement, i.e. which exceed the recommended limit in Table 4. 2. If there are any hollows, measure the point of maximum deviation from the underside of the straight edge using the graduated wedge (see Figure 5). Ensure that the straight edge is resting on the court surface either side of the hollow. 3. If there are any isolated bumps or ridges, suspend the straight edge above the peak of the bump using supports at either side (see Figure 5). Measure the point of minimum deviation from the underside of the straight edge using the wedge and subtract this value from the height of the supports. This gives the height of the bump. 4. Measure the length of the deviation by moving the straight edge either side of the maximum point, parallel to the net, until the deviation no longer exceeds the recommended limit in Table 4.

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