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Thel-mar volumetric weir

The Thel-mar Volumetric Weir is the most practical and economical calibrated measuring devise used to determine infiltration in newly installed sewer lines, as well as substantial flows in existing pipes.

The Thel-mar Volumetric Weir offers rugged construction and non-corroding materials that make our weir extremely reliable. Lehigh University testing showed the Thel-mar Weir measurements to have a +/- 5% accuracy, with a 2% accuracy at moderate and high flow rates.

Thel-mar volumetric weir

Thel-mar weirs offer the advantage of a 90 degree v-notch for measuring small infiltration flow where accuracy is of prime importance. The rectangular portion of our compound weir measures larger volume flow rates.

Thel-mar volumetric weir

Thel-mar weirs can be manufactured with an optional bubbler tube. They are produced with a 1/8" O.D. stainless steel tube attached to the right side of the adjustable ring to accommodate data logging equipment for continuous remote monitoring.

Thel-mar volumetric weir

Thel-mar Volumetric Weirs come in 6", 8", 10", 12", 14", 15", and 16" sizes, both as a standard weir or with the bubbler tube. We also carry adapters that house our 15" weir in pipes of 18", 21", 24", 27", 30", 36", 42", and 48" sizes.

Who uses Thel-mar volumetric weirs?

  • Municipalities
  • USDA
  • USGS
  • The cranberry fields of Massachusetts
  • Universities
  • Commercial and Residential developers.



10633 County Road 26
Blair, NE 68008

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