Built with proprietary sensor technology and premium materials from Switzerland, Apera LabSen 241-180 Glass Micro pH Electrode is designed for micro-volume samples in slim containers such as NMR tubes [minimum sample volume: 50 microliters]. LabSen Glass Membrane - LabSen 241-180 pH electrode adopts an ultra-long 180mm micro cylindrical glass membrane [ø3mm], making NMR tube pH measurement easier than ever. And it can be tested at high-temperature up to 212°F. The low-resistance membrane [<450MΩ] helps you quickly get a fully stabilized reading. The electrode uses a standard BNC connector, compatible with any pH meters that use BNC connectors. No temperature sensor is built-in. Users need to have a separate temperature probe [ex: Apera Instruments MP500] to enable ATC or manually input temperature to achieve temperature compensation.