73271032
Jul 21, 1980
Dec 15, 1981
Fluid Flow Meters, Level Meters and Samplers, Structural Components of the Foregoing and Systems Comprised of Two or More of the Foregoing Used Together or of One or More of the Foregoing Used in Conjunction with Standard Types of Pipes, Flumes or Weirs Particularly for Use in Monitoring Quantity and Content of Wastewater
Electrical and Scientific Apparatus