DDM offers a convincing and versatile product range of oval gear meters that cover a low flow rate and a wide temperature range of the measured media, do not require an inlet section / outlet section and are ideally suited for tight installation spaces. These properties and their viscosity tolerance make our oval gear meters largely independent of external influences. They can be used with a wide range of measuring media.
The advantages of our oval gear meters at a glance
- High measuring accuracy
- Very suitable for high viscosities
- Excellent pressure resistance
Companies from a wide range of industries rely on DDM’s oval gear meters, including the food and beverage industry, the automotive industry, the chemical industry and many more.
In addition to our fixed range of oval gear meters, we have the necessary innovative strength and development expertise to manufacture customized oval gear meters that are precisely tailored to customer-specific requirements.
Do you need a solution for aggressive media or high system pressures? We are happy to manufacture customized versions on request. Our team looks forward to hearing from you.
In our practical guide to oval gear meters you will find many more details on the design, mode of operation, measuring media and the areas of application and benefits of oval gear meters in flow measurement.

excl. 19% VAT plus shipping costs
Connection: 1/4″ BSP F or NPT F
Measurement range: 0,01 … 1,0l/min at 30cst oil; 0,1 … 1,0l/min with water
Repeatability: ±0,1%
Output: Impuls NPN; voltage
Pressure Ranges: <10bar, <50bar, <400bar, <700bar
Temperature range: -20 – 80°C, -40 – 100°C, -40 – 150°C
Data sheet: pdf | 253 KB
excl. 19% VAT plus shipping costs

excl. 19% VAT plus shipping costs
Connection: 1/4″ BSP F or NPT F
Measurement range: 0,03 … 4,0l/min at 30cst oil; 0,15 … 4,0l/min with water
Repeatability: ±0,1%
Output: Impuls NPN; voltage
Pressure Ranges: <10bar, <50bar, <400bar, <700bar
Temperature range: -20 – 80°C, -40 – 100°C, -40 – 150°C
Data sheet: pdf | 261 KB
excl. 19% VAT plus shipping costs

excl. 19% VAT plus shipping costs
Connection: 1/2″ BSP F or NPT F
Measurement range: 0,05 … 10,0l/min at 30cst oil; 0,5 … 10,0l/min with water
Repeatability: ±0,1%
Output: Impuls NPN; voltage
Pressure Ranges: <10bar, <50bar, <400bar, <700bar
Temperature range: -20 – 80°C, -40 – 100°C, -40 – 150°C
Data sheet: pdf | 274 KB
excl. 19% VAT plus shipping costs

excl. 19% VAT plus shipping costs
Connection: 3/4″ BSP F or NPT F
Measurement range: 0,25 … 50,0l/min at 30cst oil; 2,5 … 50,0l/min with water
Repeatability: ±0,1%
Output: Impuls NPN; voltage
Pressure Ranges: <10bar, <50bar, <400bar, <700bar
Temperature range: -20 – 80°C, -40 – 100°C, -40 – 150°C
Data sheet: pdf | 240 KB
excl. 19% VAT plus shipping costs

excl. 19% VAT plus shipping costs
Connection: 1″ BSP F or NPT F, R21.50, G1-11
Measurement range: 0,5 … 100,0l/min at 30cst oil; 4,0 … 100,0l/min with water
Repeatability: ±0,1%
Output: Impuls NPN; voltage
Pressure Ranges: <10bar, <50bar, <400bar
Temperature range: -20 – 80°C, -40 – 100°C, -40 – 150°C
Data sheet : pdf | 233 KB
excl. 19% VAT plus shipping costs

excl. 19% VAT plus shipping costs
Connection: 1 1/2″ BSP F or NPT F
Measurement range: 2 … 200l/min at 30cst Öl; 10 … 200l/min with water
Repeatability: ±0,1%
Output: Impuls NPN; voltage
Pressure Ranges: <10bar, <50bar, <400bar,
Temperature range: -20 – 80°C, -40 – 100°C, -40 – 150°C
Data sheet: pdf | 225 KB
excl. 19% VAT plus shipping costs

excl. 19% VAT plus shipping costs
Connection: 2″ BSP F or NPT F
Measurement ranges: 5 … 500l/min at 30cst oil; 20 … 500l/min with water
Wiederholbarkeit: ±0,1%
Output: Impuls NPN; voltage
Pressure Ranges: <50bar
Temperature range: -20 – 80°C, -40 – 100°C, -40 – 150°C
Data sheet: pdf | 220 KB
excl. 19% VAT plus shipping costs
The areas of application of oval gear meters
The precision of the measurements and the suitability for liquids of all types make oval gear meters a popular and indispensable flow meter in industry. Oval gear meters can be found in numerous applications in which manufacturers rely on accurate volume metering.
These include:
- test benches
- production systems
- laboratory technology
- dosing devices for highly viscous media
- food technology
- small installation spaces
- aggressive applications
Suitable measuring media
Oval gear meters are characterized in particular by their ability to measure a wide variety of media. Modern oval gear flow meters can handle viscous liquids such as greases, adhesives and concentrates as well as water-like solutions.
A variety of media can be precisely measured with an oval gear meter. These meters are capable of measuring a wide range of media over a temperature range from -40 °C to 150 °C. In addition, oval gear meters can be used at process pressures of up to 700 bar, which underlines their versatility in demanding applications.
Thanks to their function as volume meters, oval gear meters are insensitive to gases or air bubbles in the measured medium. In contrast to ultrasonic flow meters, which can be affected by air bubbles in the medium, oval gear meters provide reliable measured values even under such conditions.
The measuring media that can be recorded with an oval gear meter are extremely diverse and include, among others:
- Oils
- Lyes
- Acids
- Solutions
- Dispersions
- Polymerizations
- Polycondensates
- Alcohols
- Fats
- Paints and varnishes
- Reagents
- Surfactants
Special oval gear meters with adapted materials and designs are required for highly viscous, abrasive or corrosive measuring media. We are happy to advise on customer-specific requirements and manufacture customized, individual solutions.
Specifications of the oval gear meters
Important criteria for oval gear meters are the flow rate, the permissible temperature range, the operating pressure, the sealing material, the measuring sensors, the thread and the protection class. The performance of the measuring devices is consistently on the following value scale:
- Flow rate: 0.03 to 500 l/min (> 30mm2 /s oil) and 0.15 to 500 l/min (water)
- Permissible temperature ranges: -20 to 80°C; -40°C to 100°C and -40 °C to 150 °C
- Operating pressure: 10 bar to 700 bar
- Seal material: Viton (FKM), EPDM, Nitrile (NBR), PTFE, Kalrez (FFKM)
- Housing material: stainless steel 316, aluminum, PEEK, Hastelloy C
- Measuring sensor: Hall effect (NPN), reed switch, reed switch (hazardous area) NAMUR sensor
- Thread: BSP P, NPT, others on request
- Protection class: IP67/NEMA 4 protection
Design of oval gear meters
Oval gear meters consist of two oval gears mounted on a shaft with bearings in the housing. The oval wheels have gearing and roll on top of each other, ensuring synchronous rotation. Two magnets are embedded inside one of the two oval wheels. These magnets rotate continuously past the sensors in the housing cover due to the flowing measuring medium. Each pulse detected by the sensor corresponds to one rotation of one of the oval wheels, which enables the flow volume to be determined precisely. Two pulses from the oval gear meter correspond to one full rotation of the oval gear.
As the oval gear meter functions as a volumetric flow meter , the volume is not created between the gears, but between the oval gear and the housing. The measured medium – whether viscous or thin – therefore does not flow between the wheels, but is transported through the chamber between the oval gear and the housing. This design ensures that the meter also works reliably with highly viscous media.
The gear wheels of the sensors are arranged parallel to each other and mesh perfectly, which ensures synchronous rotation. This allows the flow rate to be determined extremely precisely with a Hall sensor. The pulse output signal can be processed directly by the customer or displayed using Pulsit-Solo. The Pulsit Link converter offers the option of obtaining a linearized current, voltage or frequency output signal.
The O-ring in the housing ensures a reliable seal towards the cover and prevents the medium from escaping. In addition, the material of the oval gear meters can be individually selected by the customer depending on the requirements and area of application in order to meet the requirements for corrosion resistance, temperature resistance or abrasion resistance.
Installation of oval wheel meters
The installation of oval gear meters must be designed in such a way that the oval gear meters are designed in the manner specified by the manufacturer and installed in the recommended position. The connection is made directly with a pipe or hose and the devices do not require any inlet or outlet sections. It is also important that the meter is installed in the direction of flow.
The pipes themselves must be carefully cleaned of dirt and the connections sealed to eliminate the risk of leaks.
Solids must not be contained in the measured media, otherwise a filter with a maximum mesh size of 80 µm must be installed upstream of the oval gear meter.
The oval gear meter must be selected according to the pressure, viscosity and temperature range of the medium. This suitability can be found in the manufacturer’s specifications. The meter must be connected electrically in accordance with the specifications in the operating instructions.
Signal output and data processing
DDM’s oval gear meters provide a pulse output signal (PNP or NPN) that can be processed directly by a PLC or other evaluation electronics. The signal can be linearized using the data from the supplied calibration certificate, which further increases the measurement accuracy.
The Pulsit Solo is available as a simple display that can be connected directly to the oval gear meter. It displays both the current flow rate and the measured total volume.
The Pulsit Link also offers the option of linearizing the measurement signal and provides various output signals, including current (0-5VDC, 0-10VDC), voltage (4-20mA) and TTL pulse. The measurement results can be integrated directly into programs such as LabVIEW via the ASCII interface. In addition, the Titan Interface software allows the flow meter to be connected directly to a computer using the Pulsit Link. This allows the settings to be configured, the current flow rate to be displayed in real time and the measurement data to be recorded.
DDM expert tip
In demanding industrial environments with ambient temperatures between -40 and 125 °C, we recommend signal processing using a flow computer (VCA), which is also available in a CAN bus version in addition to current and voltage outputs.
Calibration and maintenance of oval gear meters
The correct calibration and maintenance of oval gear meters are crucial for their long-term reliability and accuracy. To calibrate the meter, it is compared with a reference meter. To do this, a known quantity of liquid is passed through the meter and compared with the measured volume. Annual calibration is recommended to ensure the performance of the device.
Maintenance also includes cleaning the oval gear meters to remove all residue from the devices. This is only necessary if the oval gear meter falls significantly short of its usual performance during calibration. The device must be cleaned in such a way that the sensitive equipment is not damaged. Bearings and seals must be checked for wear and the filters must be checked for functionality.
Oval gear meters for special requirements
DDM offers individual oval gear meters with outstanding performance in various key figures, the specifications of which are determined by our customers.
We develop and design oval gear meters together and in close cooperation with our customers so that they are tailored precisely to their needs and optimally meet the specific requirements of the respective application.
Order or request oval gear meters online
DDM specializes in flow measurement under extreme conditions and offers displacement meters with the highest quality, an impressive range of functions and high reliability even in critical industrial environments.
Our customers can obtain customized, individual products from us that fully meet their specific requirement profiles.
Be inspired by our product selection, order directly from our online store in just a few clicks or request individual configurations. We look forward to receiving your inquiries and tasks.