Lissajous technique

Today, corona discharge is the electrical method used most widely and is one of the most popular for preparing the surfaces of polyolefin films. It relies on establishing a corona discharge between an electrode and an earthed roller covered by a dielectric layer the film is passed over the roller and the discharge renders the surface of the film receptive to inks. Sherman and co-authors12 described the theoretical electrical relationships in the treatment equipment and by means of the Lissajous technique for measuring power demonstrated how much true power was dissipated in the material under treatment. Table XX lists some relevant patents. 

The alternate method uses the proximity probes and an oscilloscope. A Lissajous figure is established on the oscilloscope. The orbit pattern and the keyphase mark are used to generate a vector. Weights are added or removed and the changes in the orbit are noted. Triangulation is used to anticipate the next move. For more complete information or technique, the reader is referred to a book on the subject by Jackson [ 1 ]. 

Ihe paper of Ref 2, abstracted in Ref 3> reports a technique that will yield insight into the quality of EBW devices in a nondestructive manner. By employing a self-balancing bridge it is possible Co ascertain die electrothermal and nonlinear behavior of the device. A sinusoidal current is passed thru the device which provides a signal in the form of a unique Lissajous Display (See Note, below). This display can be qualitatively evaluated and abnormal units can be readily detected... 

Recording the applied av potential and the resulting ac current on a twin-beam oscilloscope produces Lissajous curves (in this case an ellipse), which may be used to the determine the impedances. Because of its frequency limitations and sensitivity to noise, this technique is not currently used in electrochemical measurements. 

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