The H.OIL oil, water interface meter is used to measure the interface level between two liquids in the same tank, vessel, well or aquifer. The dissimilar density of two liquids means the lower density, non-conductive product (LNAPL) will float on top of the higher density, conductive liquid (water). Denser products will tend to sink (DNAPL), creating a layer under the water. The Heron H.OIL can detect these layers with mm precision. The premium padded carry case comes included to protect your precision instrument from the elements. The hydrocarbon resistant Kynar jacketed, high tensile steel core tape is able to withstand hydrocarbons, solvents and other harsh contaminants. The Durable Jacketed Steel Tape is Certified/Compliant to – ASME B89.1.7-2009 & MIL-STD-45662A Certified, FED GGG-T-106F & EEC Class II Compliant The intrinsically safe certification makes the H.OIL ideal for use in hazardous environments by Oil & Gas, Chemical and Petrochemical Industries. The H.OIL is approved for use in zone 0 deployments. ATEX.