Flow meters for water

Flow meters for water

Efforts to reduce water consumption presuppose knowledge of the current consumption. Measuring systems such as magnetic-inductive or ultrasonic flow meters detect the three process categories volumetric flow quantity, consumed quantity and medium temperature. They are frequently used in cooling circuits, e.g. in steelworks, the automotive industry and in glassmaking. In water management and industrial installations, the sensors are used for water consumption measurement.
Peak consumption, present consumption or accumulated consumption can be accessed and adjusted via programmed switch and alarm level settings - all at the touch of a button.
The range also includes types for use in drinking water supply.

What Is a Digital Water Flow Meter?

A digital water flow meter is an electronic measuring device designed to detect and monitor the flow of water in industrial systems. It provides real-time measurement output via a digital interface or to a PLC for automated control. At ifm, digital flow meters are used in a range of applications—from cooling circuits and pump monitoring to process water management—ensuring efficiency, system protection, and accurate consumption tracking.

How Does a Water Flow Meter Work?

ifm flow meters operate using non-mechanical, wear-free sensing technologies to ensure long-term reliability. Depending on the model, the measuring principle may include:

• Magnetic-inductive: Measures flow of conductive media using Faraday’s law. Common in water and coolant systems.

• Vortex: Detects vortex shedding frequency behind a shedder body to determine flow rate.

• Thermal: Uses heat dissipation on a sensor probe to monitor flow velocity, ideal for low flow rates or leak detection.

These meters convert flow data into standardised outputs (analogue, frequency, or IO-Link), allowing for direct integration into automation systems.

Types of Water Flow Meters

ifm offers several digital water flow meter technologies, including:

Magnetic-inductive flow meters (e.g. SM series)

• Designed for conductive media such as water or aqueous solutions.

• No moving parts, making them ideal for wear-free operation.

Vortex flow meters (e.g. SV series)

• Used in cooling circuits or process systems requiring simultaneous flow and temperature measurement.

• Particularly suited for harsh industrial environments.

Thermal flow sensors (e.g. SI or SBY series)

• Measure flow based on thermal dispersion.

• Used for applications such as dry-run protection of pumps, low-flow detection, and water circuit monitoring.

Advantages and Disadvantages of Digital Flow Meters

Advantages

• No moving parts: Ensures long service life and low maintenance.

• High repeatability and accuracy: Suitable for precise flow monitoring and control.

• Multiple outputs: Models offer switching, analogue, frequency, or IO-Link outputs.

• Combined measurements: Some versions offer flow, temperature, and volume in one device (e.g. vortex flow sensors).

Disadvantages

• Media limitations: Magnetic-inductive meters require conductive liquids.

• Installation requirements: Some sensors require defined inlet/outlet pipe lengths for optimal accuracy.

• Cost: Higher initial investment than mechanical meters, but lower lifetime maintenance costs.

How to Choose the Best Water Flow Meter

Choosing the right digital water flow meter depends on your medium, measurement needs, and environmental conditions. According to ifm, consider the following:

1. Type of liquid

   • Use magnetic-inductive sensors for conductive water-based fluids.

   • Choose vortex or thermal sensors for non-conductive liquids or mixed media.

2. Flow rate and pipe size

   • Select a meter that fits the flow range and pipe diameter of your system. ifm offers compact and inline models for easy integration.

3. Required outputs

   • Decide whether you need switching outputs, analogue signals, or IO-Link communication for integration into a digital network.

4. Installation environment

   • For high vibration, dirt, or heat, rugged sensors like ifm’s SV series offer robust stainless steel designs with high ingress protection.

5. Additional monitoring

   • Some ifm flow sensors measure both flow and medium temperature, reducing the need for multiple devices.