Flow meter technology plays a crucial role in various industries, providing accurate measurements of fluid flow rates. These devices, designed to measure the rate of flow of liquids or gases, come in various forms, each tailored to specific applications. But how do these work? Let's explore the inner workings of paddlewheel, turbine, ultrasonic, and oval gear flow meters, shedding light on their distinct features.

View PADDLEWHEEL insertion flow meter.

Paddlewheel Flow Meters

• Measure the flow of water, fuel, and other low-viscosity liquids.
• Extremely versatile; suited for a huge variety of pipe sizes
• Only one moving part; provides a reliable product with minimal maintenance costs.
• Moderate measurement correctness

Nutating Disc Flow Meters

• Measure the flow of water, glycols/anti-freeze, diesel exhaust fluid (DEF/Adblue®), lubricating oils and greases, fertilizers, herbicides, insecticides, and water-based chemicals
• No requirement for flow conditioning or straight lengths of pipe before and after the meter
• Good turndown ratio of up to 100:1
• Can tolerate small particles such as sand and sediment
• Operational in only one direction

Turbine Flow Meters

Turbine flow meters use the mechanical energy of the fluid to rotate a "pinwheel" (rotor) in the flow stream. The blades on the rotor are angled to convert energy from the flow stream into rotational energy. The rotor shaft spins on bearings. When the fluid moves faster, the rotor spins proportionally faster.

Turbine flow meters excel in applications that require high accuracy and a wide flow range.

• Extremely versatile design accurately measures both high- and low-viscosity fluids.
• High-accuracy and repeatability measures every drop and reduces waste in your process.

Suits Pipe Sizes	1/2" - 4" (15 - 101 mm)
Flow Range*	3.8 - 1135 L/min
Accuracy*	± 1.5% - 5% of Reading
Temperature Range*	-40°F to 250°F (-40°C to 121°C)
Operating Pressure*	150 psi (10.3 bar) - 300 psi (21 bar)

* Ranges vary depending on meter, material, and size

View ULTRASONIC flow meters.

Ultrasonic Flow Meters

Ultrasonic flow meters transmit and receive a burst of ultrasound between two transducers. Transit time is measured in both directions. By analyzing the time it takes for the pulses to travel upstream and downstream, the fluid velocity can be calculated with exceptional accuracy. Since no moving parts are required to detect flow, it continues to measure accurately even in low-flow situations.

• Easy installation
• No moving, wearable parts; low-to-zero maintenance
• Low total cost of ownership
• High accuracy and repeatability, measures every drop and saves waste in your process.

Suits Pipe Sizes	1 - 12" (25 - 305 mm)
Flow Range*	0.1 to 15 fps (0.03 to 4.6 m/s)
Accuracy*	± 2% of Reading
Temperature Range*	-32°F to 140°F (0°C to 60°C)
Operating Pressure*	203 psi at 73°F (14 bar at 23°C) 150 psi at 140°F (10 bar at 60°C)

* Ranges vary depending on meter, material, and size

View OVAL GEAR flow meters.

Oval Gear Flow Meters

Oval gear flow meters are a type of Positive Displacement flow meter used to measure the volumetric flow of liquids. These meters directly measure the volume that passes through them rather than the velocity or other physical characteristics of the liquid to calculate the volumetric flow rate, making them volumetric meters.

• Accurate with clean, viscous fluids, unaffected by temperature changes
• No flow conditioning required; they can be placed directly after pumps or valves with no effect on accuracy.
• Robust
• High turndown rates
• Low pressure drop
• Excellent for small volume additions

Suits Pipe Sizes	1/8 - 4" (4 - 100 mm)
Flow Range*	0.5 - 2500 L/hr
Accuracy*	± 0.5% - 1% of Reading
Temperature Range*	-40°F to 300°F (-40°C to 150°C)
Operating Pressure*	50 psi (3.45 bar) - 1450 psi (100 bar)

* Ranges vary depending on meter, material, and size

Certifications/Approvals

(check product page/datasheet to check which apply to the meter)