5.1 The deformation and end point of a cone corresponds to a certain heat-work condition due to the effects of time, temperature, and atmosphere.
5.2 The precision of this test method is subject to many variables that are difficult to control. Therefore, an experienced operator may be necessary where PCE values are being utilized for specification purposes.
5.3 PCE values are used to classify fireclay and high alumina refractories.
5.4 This is an effective method of identifying fireclay variations, mining control, and developing raw material specifications.
5.5 Although not recommended, this test method is sometimes applied to materials other than fireclay and high alumina. Such practice should be limited to in-house laboratories and never be used for specification purposes.