The H.OIL oil/water interface meter from Heron Instruments Inc. is used to measure the thickness of floating product (LNAPL) above the water table. It also will detect and measure sinking layers of DNAPL. With its 5¿inch slim probe, the H.OIL may be used with wells, piezometers and direct push equipment as narrow as 3¿inch in diameter. The probe and tape will withstand hydrocarbons, solvents and other contaminants, and the meter is suitable for wells, boreholes, and underground and above ground storage tanks. Heron Instruments Inc., Card No. 36