Sessile Drop or Adhering Gas Bubble Method

The contact angle can be measured using a telescope fitted with a goniometer eye piece. Alternatively, it can be measured by taking a photograph or using image analysis. 

Care must be taken for kinetic effects and evaporation. 11.11.2 

The substrate in the form of a thin plate is attached to an electrobalance to measure the force. Two procedures may be applied The plate is allowed to touch the 

A/) is the density difference between the plate and the liquid and V is the volume of liquid displaced. 

The above method is convenient and allows one to measure 0 as a function of time. Also, Fa and Fr can be determined by raising and lowering the liquid in the vessel (using a lab jack). 

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