The Model IT is designed to take potential readings in any application where a standard, liquid junction portable reference electrode is presently being used. Because it contains a gel rather than a liquid, it will neither leak nor require any refilling or cleaning. The hardwood plug offers several advantages over the conventional ceramic membrane. It will not clog as readily, it is resistant to salt blockage, and it can be reworked by light sanding or cutting if it becomes contaminated with oil. All units have antifreeze protection in the gel so that they will not be damaged if exposed to temperatures down to -35oF.