The indicated thickness of any piled or raised floor covering depends considerably on the load being exerted on it during measurement of thickness. Also, the indicated thickness gets reduced progressively as the load acting on it is increased. Thus it is necessary that the thickness is determined under a specified load so that the value determined could be considered standard.
A carpet thickness gauge is used for determining the thickness of the floor covering under a specified load. It can also be used for determination of thickness under different loads, thus giving an indication of the resistance of floor covering to compression under load, as well as its ability to recover from the effects of such loads after the load is removed.
The Carpet Thickness Gauge is designed to measure the thickness of floor coverings under different loads. It consists of a rigid metallic frame having a loading rod held with its axis vertical, capable of moving freely within two brass guide bushes. The rod has a flat cylinder indentor mounted on its lower end and a small metallic disc mounted on its body. Slotted disc weights of appropriate loading capacity can be placed on the disc to enable different loads to be applied on the floor covering under test. The rod and the load can be raised or lowered with the help of a lever arm.
A dial indicator is provided above the loading rod. The tip of the dial indicator can be brought in contact with the upper face of the rod. An electrical system consisting of an LED and dry cells is provided to enable the thickness to be measured without the force of the dial indicator acting on the surface of the floor covering under test.
BS 4051 - 1972 : Method of Determination of Thickness of Textile Floor Coverings
ISO R 1765 : Machine Made Textile Floor Covering Determination of Thickness.