ABSTRACT
Equation (15) was used to obtain the meniscus height As seen in Fig. 27, and indicate the nondimensional coordinate of the meniscus at the attachment position and the inclination of the test plate, respectively. The gradient of the meniscus curve becomes equal to that of the solid wall (i.e., shown in the figure) at C. Hence the coordinate of the contact, can be calculated by using instead of ψ in Eq. (15) as
(56)
Using the above equation, the coordinate of the contact, can be obtained geometrically as
(57)
Now we use Eq. (14) for the meniscus profile. When is substituted into the right-hand side of Eq. (14), the result should be equal to Eq. (57). Hence we can determine the integral constant C in Eq. (14) under the critical condition. Substituting the calculated C and at the attachment position of the meniscus to the test plate S1 into Eq. (14) again, shown in Fig. 27 can be obtained as follows:
(58)
Finally, the critical height shown in Fig. 27 is written as follows if Eq. (58) is inserted into Eq. (55):
(59)
When i.e., the inclination of the meniscus from the horizontal at the test plate, becomes greater than the meniscus does not contact support S2 until it reaches B, as shown in Fig. 28. In this case, the three-phase contact line might be trapped at the corner between S1 and S2 because the tip of S2 would be slightly rounded. The meniscus would not break off
