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Select the perfect electronic flow meter for your application requirements

ifm's product range of flow sensors offer different measuring principles, materials, and displays to meet the requirements of different industrial manufacturing plant operations across the U.S. ifm’s complete family of flow sensors enable you to have the right technology for your application at a price point that allows installation of more monitoring points for better process control and feedback. Many models also provide process temperature and totalizer data giving you more insight into your process.

Use the “Select by application” table below to narrow your search for a flow sensor and read more about the underlying measuring principles and technology of a sensor group by finding the orange “Learn More” row. 

 

Media
Wated-based conductive media
(>20μs/cm)
Deionized water /
non-conductive media
Oils
Glycol
 Compressed air
 Gases (Ar, CO2, He, N2)
Specifications
Line size 1/4" - 2" 1" - 2" 1/2" - 3/4" 1/2" - 1 1/2" 1/2" - 2" 2" - 16"
Accuracy ~ ±1% ~ ±2% ~ ±2% ~ ±5% ~ ±3% ~ ±10%
Medium temperature 14…158 °F
-4...194 °F (units with TFT display)
-4…212 °F
-20…100 °C
14…194 °F
-10…90 °C
14…212 °F
-10…100 °C
32…140 °F
0…60 °C
-4…212 °F
Higher upon request
Pressure drop
Totalizer function
Price
Magmeters,
Type SM
Ultrasonic,
Type SU
Vortex,
Type SV
Mechatronic,
Type SB
Thermal inline,
Type SD
Thermal,
Type SA
 : Ideal application  : Do not use in application : Proceed with caution  : Less pressure drop

Technology overview

Magnetic inductive

Operating according to Faraday's law of induction, when a conductive medium flows through a magnetic field, a voltage proportional to the flow velocity/volumetric quantity is generated. The voltage is tapped via electrodes and converted in the evaluation electronics to a usable control signal.

Ultrasonic

Ultrasonic flow meters consist of transducers that transmit and receive sound pulses. Medium on the opposite pipe wall diverts the direction of the transmitted pulse from one transducer to the other. A pulse is sent through the medium and the sensor measures the time of flight from one transducer to the other. Then a pulse is sent in the opposite direction. The meter measures the difference in time and calculates the flow rate. 

Vortex

The vortex flow principle is a proven method for measuring flow of water based liquids. Behind a blunt body integrated in a measuring pipe, the flowing liquid generates vortices that are detected by a piezoceramic sensor. Since the cross-section of the pipe is known, the number of vortices determines the flow rate, independent of the liquid's pressure and temperature fluctuations.

Mechatronic

The SB Mechatronic flow meter works on the principle of a spring supported piston. Flowing liquids lift the piston and the postion of the piston is monitored by a magnetic sensor. The spring forces the piston to it's original positon with decreasing flow and the built-in check valve prevents back flow. Since flow is typically relatively stable, there is very little flexing of the spring. The meter has been successully tested to 10 million cycles without any detectable wear.

Thermal

Thermal flow sensing technology relies on the cooling effect of flowing liquids or gases. A higher flow velocity results in a greater cooling effect and this can be reliably measured. The image (to the right) depicts heat being conducted from the sensor tip by a flowing liquid.

For the SA and SI families, two platinum RTD elements and a heater are in the sensor tip. The reference element monitors the temperature of the medium and it is located 10 - 15 mm from the bottom of the tip.  The difference in temperture between the two RTDs is held constant (4 °C) by varying the amount of power applied to the heater. The power required to maintain the temperature difference is directly proportional to the flow rate.

For compressed air applications, the SD design also uses thermal technology. In this case one ceramic probe is heated (the measuring resistor) and the other is not (reference resistor). Flow velocity is determined by the voltage difference between the two resistors when the flow dissipates the heat.