Starting at $568.00

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A completed DON application data form is required to purchase this meter. We will contact you about your order.


  • 0.13 to 9.5 GPH up to 40 to 660 GPM flow rates
  • ±0.2 to 1% accuracy, depending on configuration
  • Bi-directional flow sensing
  • 1/8 up to 4in line sizes
  • Aluminum or stainless steel construction
  • Threaded or flanged fitting
    • NPT, BSP, ANSI, or DIN
  • 250°F (121°C) max operating temp

The Kobold DON Series Oval Gear Flow Meters measure clean, high and low viscosity liquids such as lubricating/hydraulic oils, diesel fuels, chemicals, solvents, resins and pastes. This flowmeter uses two precision-machined oval gears which allow for a very specific volume of liquid to pass through the meter with each rotation. These gears enable the DON flow meters to precisely measure liquid flow over a very wide viscosity range.

The Oval Gear meters are positive displacement flowmeters where the flow of liquid causes two oval gears to rotate within a precise measuring chamber and with each rotation a fixed volume of liquid passes through the meter. Magnets embedded within the gears are sensed to create a high resolution pulse train output. The pulse output can be wired directly to process control and monitoring equipment or can be used as an input to a conditioning electronic or display supplied with or attached directly onto the meter.


This product can be used in the following applications:

Application Notes

Here's how some of our customers used this product.

High Viscosity Fluid Test Lab Meter

The Background: Our customer is a large food company that seeks a flow meter for use in their product development test lab.

The Problem: The test lab will need to measure the flow of food products, some of which have a very high viscosity (in excess of 10,000 centipoise) over a range of pressures and temperatures.

The Solution: We recommended the Kobold DON Series Oval Gear Flow Meter. The design of gear meters allows for very accurate and repeatable flow measurements over a very wide viscosity range and in varying process conditions.