The Orion 9409BN Half-Cell Fluoride and Orion 9606BNWP Combination Fluoride Electrodes measure free fluoride ions in aqueous solutions quickly, simply, accurately and economically. The measurement of fluoride in drinking water is an approved ASTM method: Approval number ASTM D 1179. Orion 9609BNWP Fluoride (F-) Sure-Flow combination electrode and Orion 9409BN Fluoride (F-) half-cell. Teamed with the introduction of the Orion Star Series, Thermo Scientific has also introduced the new WP- waterproof and secure electrode connectors, a revolutionary feature of the new Orion Star Series Meters. The BNWP connector provides a waterproof and secure connection when used with the new Orion Star Series meters. The BNWP connector is compatible with any standard BNC connector both on Orion meters and competitive meter models. U.S. Standard and waterproof BNC electrodes have 1 m cables. Screw cap connector requires separate cable.