GRX-Q Flow Sensor – Volume Flow Sensor for Oils and Lubricoolant Emulsions

Product Advantages
  • Easy assembly
  • Almost wear-free
  • Measurement accuracy of < 5%
  • Suitable for all commercially available monitoring systems
  • Direct connection to the Grindaix CMS (plug & play)
  • Can be used independently for emulsions and oils
  • Optical function displays, programmed limit values
  • 3 sizes: < 150 l/min, < 250 l/min, < 450 l/min
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In many places, the volume flow measurement in lubricoolant systems occurs only rarely via external measuring devices, or it takes place manually. To monitor the lubricoolant supply of machine tools in future, robust volume flow sensors are indispensable in the context of the Industry 4.0 initiative. However, due to contamination of the lubricoolant, volume flow sensors available on the market are often highly prone to wear and thus cost-intensive.

As an alternative to the use of measurement technology that is susceptible to wear, the team at Grindaix GmbH has developed an almost wear-free volume-flow sensor for lubricoolants. It is based on the principle of the report published by Giovanni Battista in 1797 on the “Venturi Effect”.
With the aid of innovative 3D printing technology, a reliable sensor has been developed which offers this measuring effect with only low pressure losses for the lubricoolant supply of machine tools.

The measuring principle combines excellent wear strength with very high measurement reliability (< 5%). To record the measurement values, no moving parts are required in the medium. This leads to a robust and durable volume flow sensor.

To show the volume flow we recommend the use of our Coolant Display. The sensor was developed for various volume flow classes. The smallest sensor measures in the range of < 150 l/min.

GRX-Q is suitable for carrying out virtually wear-free volume flow measurements of almost all fluids. In addition to the volume flow, the pressure in the pipe system and the prevailing media temperature are also measured at the same time. Each sensor leaves Grindaix after undergoing a test operation for determining the exact product characteristic curve.


Connection flange: DN25 / DN32

Analog output signal: 4 – 20 mA / 0 – 10 V

Operating pressure: 0 - 16 bar

Operating temperature: 0 - 60 °C

Response time: <1s (97% – real value)

Sampling rate: up to 25 ms

Grindaix_Volume_flow_sensor.pdf pdf 1.090 KB download

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Sensor functions - 3 in 1

Through a network connection with the GRX-Q parameterization software, it is possible to obtain the characteristic data for each viscosity and for each type of coolant. This means that all liquids such as cooling lubricants, as well as gases and vapours, can be used, even at extreme temperatures, fast flows, high pressure or corrosive media, where direct volume meters are not always available.

3 in 1: The Grindaix volume flow sensor allows you to monitor limit violations of three process data simultaneously: Pressure, flow rate and temperature, in only one sensor! In addition, all connected sensors can be parameterised simultaneously with just one click. This eliminates the need to replace mechanical components, and your production no longer suffers from system downtime.

The maximum error rate of 5% promises a particularly high measuring accuracy and is therefore considerably higher than with standard sensors. Furthermore, a very high wear resistance is guaranteed by the additive manufactured tube geometry.

Operating conditions

The Grindaix volume flow sensor is able to indicate its operating status (e.g. fault, medium flowing, ...) at any time by means of different colours. The picture below shows an example of the different states:

The colour

  • green stands for "Ready for operation
  • yellow stands for "Warning"
  • red stands for "error".

GRX-Q function

The sensor function is based on the differential pressure method, which uses a defined change in cross-section to determine the volume flow via a differential pressure. By means of an additive manufactured basic body it is possible to create an optimal inner contour of the measuring tube. This enables low pressure losses with low wear and tear. The GRX-Q volume flow sensor can be configured for a wide range of media using parameterisation software.


Product brochure

We have summarised all important information about the Grindaix volume flow sensor in our product brochure.

(Please click to open)

Cost calculation

The cost of one hour of operation (including acquisition costs) of the GRX-Q, amounts to 0.05 €, with a useful life of 10 years, 220 days/year in three-shift operation!

Integration into the monitoring technology

The volume flow sensor offers a direct connection via network cable to the Grindaix Coolant Monitoring System, so no further analogue/digital conversion is necessary. The Coolant Monitoring System provides a machine interface, which ensures cycle-related monitoring.

Further accessories are the Coolant Monitoring Pad and the Coolant Condition Guard.