Cole-Parmer's range of oval gear flow meters for liquids offer high accuracy and each one comes with a factory calibration report. They are simple to install and can be combined with a wide range of displays and controllers to provide effective solutions for a wide range of metering and batch control applications. Cole-Parmer offers gear flow meters for measuring liquid flow from 8 ml/min to over 250 LPM.

Cole-Parmer's gear flow meters are unaffected by viscosity and can be used with media between 1 and 1,000 centipoises. The gear flow meters are available in a range of materials including 316 stainless steel. Options available include a range of ATEX gear flow meters suitable for installation in to an ATEX zone 1 environment.

To find the right flow meter for your application use Cole-Parmer's on-line flow meter quick search. Alternatively contact our Application Specialists for free technical support and let us bring over 50 years of flow control experience to help solve your application needs.

Key Points for gear flow meters

Figure 1.








• Oval gear flow meters are a type of positive displacement flow meter and utilize gear-toothed rotors that rotate within a chamber of specified geometry (Figure 1). As these rotors turn, they sweep out and trap a very precise volume of fluid between the outer oval shape of the gears and the inner chamber walls, with none of the fluid actually passing through the gear teeth. Normally, magnets are embedded in the rotors, which then can actuate a reed switch or provide a pulse output via a specialized, designated sensor (such as a Hall Effect sensor). Each pulse or switch closure then represents a precise increment of liquid volume that passes through the meter. The result is high accuracy and resolution, with almost negligible effects for varying fluid viscosity, density and temperature.
• A gear flow meter has high accuracy of typically ±0.5% of reading
• A gear flow meter normally has a turn down ratio in the region of 100:1
• Gear flow meters need particulate free liquids and it is recommended that a strainer is placed as close to the inlet of the meter as possible to remove particles that could cause wear or block the meter.
• A gear flow meter does not require a straight pipe run before the flow meters inlet
• The gear flow meter works best when there is a little backpressure in the line; a throttling valve on the meter outlet typically works just fine.

Advantages for gear flow meters

• High accuracy
• Flow measurement is independent of viscosity
• Simple to install - no straight pipe runs required
• Pulsed output allow connection to a wide range of displays and controllers including options for flow rate, totalised flow, batch control and connection options to a PC or PLC for control

Disadvantages for gear flow meters

• Particulates can lead to line blockages
• Can be damaged by sudden changes in flow
• Meter can be more bulky than other flow technologies

Typical Application for gear flow meters

• Metering of methanol or fuel particularly when used for fiscal measurements and custody transfer
• Measurement of high viscosity fluids in the manufacturing process
• Measurement of viscous fluids in the lab
• Measurement of viscous water additives
• Verification of proper bearing-lubricant delivery in hydraulic applications
• Monitoring of paper-finishing chemicals
• Monitoring the flow of wax finishes
• Monitoring syrup injection in main beverage lines
• Monitoring batching volumes of thick candy coatings
• Monitoring and automating the dispensing of cooking oils