AxialIon Path® Reference· Patented designincreases sensor life, accuracy and reliability· High resistance topoison: Reduced calibration offset error· Large surface areareference junction eliminates plugging issues· Eliminates error dueto fluctuating pressure· No exotic gel orpolymer electrolyte which may be incompatible with the processIn some in-line applications sensor removal forroutine cleaning or calibration becomes difficult due to conduit or cabling.The 551 Quick Change Sensor offers a unique method to extract the sensorthrough a œNut Lock Adapter system. The Nut Lock Adapter threads directly into1 inch NPT process connections. Sensor length options up to 12 inches allowsthe sensor to fit through flanges and stand-off piping. The 551 sensor alsoincludes a 3\/4 inch rear connection for use in submersible applications.Insertion DepthThe depth that pH \/ ORP sensor protrudes into the pipelinecan greatly affect the measurement. Applications where the sensor tip isrecessed can lead to coating and slow response. In high particulateapplications abrasion of the electrode can be a concern.A typical installation goal is to get the sensor tip at least1\/4\" (6mm) into the stream. At this depth coating issues lessen andresponse improves due to flow velocity. 546, 551 and 547 sensors offer avariety of insertion depths. Here are some guidelines.