Solinst Model 101 [114310] Water Level Meter with P7 Probe & Metric Increments, 600m. The Model 101 P7 Probe Water Level Meters are the industry standard for portable hand-operated meters to measure the depth of water in wells, boreholes, standpipes, and tanks. They are sturdy, easy to use, and read accurately up to 1/100 ft. or each millimeter. The Model 101 P7 Water Level Meter features a pressure-proof probe rated at 500 psi and laser-marked PVDF tape. The P7 Probe is submersible up to 1000 ft. (300 m), ideal for measuring total well depth. The sensor at the tip of the probe provides consistent measurements with almost zero displacements. The tape seal plug design allows the probe to be quickly and easily replaced if required. The Model 101 P7 Probe Water Level Meter uses extremely durable PVDF flat tape, traceable to NIST and EU measurement standards. Each tape conductor contains 13 strands of stainless steel, and 6 strands of copper-coated steel, making the tape non-stretch and high in tensile strength and electrical efficiency. The well tape has a thick dog bone design that prevents adherence to wet surfaces and allows it to hang straight in application settings. The tape is also easy to splice. The 3/8" (10 mm) well tapes come with permanent laser markings every 1/100 ft. or each millimeter.