Battelle Memorial Institute

Melvin D Campbell

Glendon W Gee

The present invention provides a method and apparatus for in-situ calibration of distance measuring equipment. The method comprises obtaining a first distance measurement in a first location, then obtaining at least one other distance measurement in at least one other location of a precisely known distance from the first location, and calculating a calibration constant. The method is applied specifically to calculating a calibration constant for obtaining fluid level and embodied in an apparatus using a pressure transducer and a spacer of precisely known length. The calibration constant is used to calculate the depth of a fluid from subsequent single pressure measurements at any submerged position.

Apparatus for in-situ calibration of instruments that measure fluid depth

The present invention relates to improvements in tensiometers for measuring soil water tension comprising a rod shaped wick. the rod shaped wick is shoestring, rolled paper towel, rolled glass microfiber filter, or solid ceramic. The rod shaped wick is secured to the tensiometer by a cone washer and a threaded fitting.

Growing community of inventors

Richland, WA, United States of America

Melvin D Campbell