There are certain applications in which such sensors need to be rugged enough to withstand harsh conditions in factories, laboratories or out in the field. For this reason the membrane is protected by a steel mesh and the shaft is made out of glass fiber reinforced PPS (polyphenylene sulfide). To go with the InLab® 605 METTLER TOLEDO offers the best of the best accessories: membrane kit, electrolyte, sealing kit and electrode weight.