Scientific, nautical, surveying, weighing, measuring, signalling and checking and supervision apparatus and instruments, namely, apparatus and instruments for metering fluid levels, for recording fluid levels and for calculating fluid level data, measuring apparatus for determining liquid levels, apparatus for measuring compression of oil, gas, deep-water and geothermal wells, pressure and temperature probes for deep well drilling, thermometers not for medical purposes, piston rod clamps being laboratory equipment and funnels being laboratory equipment; sampling devices, namely, electronic and mechanical devices, namely, cylindrical sample vessels with level markings, valves, pressure chambers and time clocks for taking samples of earth's surface or of fluids in deep holes; Scientific apparatus for extracting samples, namely, sampler apparatus for collecting physical samples of sand from a well, down hole fluid samplers, surface samplers for oil and gas wells, sample time clocks to activate samplers for sampling oil, sand, mud, cement, water, and well fluids; Scientific apparatus for transporting samples, namely, sample cylinders and cylinder stands; apparatus for laboratories, namely, blenders and mixers for use in testing samples of oil, sand, mud, cement, water and well-fluids, electronic pH-testers and centrifuges; analysis equipment for drill samples and soil samples, namely, thermometers not for medical purposes, piston rod clamps being laboratory equipment and funnels being laboratory equipment