Measurement techniques for ion impurities in liquid crystal mixtures

A method for characterizing the presence of ions in an object under test, the method comprising:

• providing an object having a pair of electrodes attached thereto;
• applying an electrical driving signal at a given frequency to the electrodes of the object;
• measuring an electrical response signal from the electrodes;
• and
• based on the electrical driving signal and the electrical response signal, and in the absence of measuring light transmitted through or reflected off of the object, determining an ion distribution spectrum that includes a display of the number of ions present in the object versus the given frequency of the electrical driving signal.

A method for measuring a performance parameter of a liquid crystal mixture under test, the method comprising:

• providing a liquid crystal test cell having a pair of electrodes;
• placing the liquid crystal mixture under test into the liquid crystal test cell;
• applying an electrical driving signal to the electrodes of the liquid crystal test cell;
• measuring an electrical response signal from the electrodes;
• and
• based on the electrical driving signal and the electrical response signal, and in the absence of measuring light transmitted through or reflected off of the liquid crystal test cell, determining the performance parameter for the liquid crystal mixture under test;
• wherein the performance parameter is an ion distribution spectrum that includes a display of the number of ions present in the liquid crystal mixture under test versus the given frequency of the electrical driving signal.