Perfect for monitoring compressed gas flow and consumption – for use in piping systems downstream of dryers and filters.

The S401 compressed air flow meter is designed to be easy to use, affordable and it’s offering a wide measurement range.

This makes it easy for you to choose the right flow meter, the S401 which fits your needs. The S401 is a thermal mass flow meter, based on its measurement principle it’s not required to compensate the compressed air pressure and temperature, so you do not need any additional measurement installations to measure the flow and the consumption.

Suitable for many applications.

Due to the thermal mass flow, the flow meter is also well suited to be used in any other gas as Nitrogen or many other technical gases. The S401 sensor technology offers you a high resolution and a high sampling rate, which results in a very fast and precise measurement. The flow meter is able to save two calibration curves, due to this the sensor can be used in two different gases without any loss of accuracy.

The optional color display is designed to show all measured values like actual flow and total consumption. At the same time, the display can be used to manage the sensor settings like pipe diameter, gas type or output settings.

The S401 flow meter offers two different signal output options. It can be equipped with an isolated analog and pulse output to read out the compressed air flow and the total compressed air consumption. Alternatively, a MODBUS RTU interface can be used to access all measured values via the digital interface.

Easy installation. Easy removal for calibration.

Since the flow meter can be easily installed through a standard ball valve, it can be easily removed for a calibration, without shutting down your compressed air system. Various settings such as gas type, flow unit, reference standards, can be set ex factory according to your needs. If It’s needed to change the settings on site, then you can use our free S4C-FS mobile phone application for android phones. This enables you to change the settings wirelessly on site, within a touch of your smartphone. Managing your compressed air was never easier. Of course, if there are any special requests, as custom flow ranges or different gas types, feel free to contact us.

This all makes the S401 compressed air flow meter the best suited sensor for your application.

Product features

  • Thermal mass flow, independent of pressure and temperature changes
  • Measures standard flow, mass flow and consumption
  • Installation under pressure through 1/2” ball valve
  • Sensor can be calibrated in 2 different gases
  • Selectable gas type (Some gases require real gas calibration!)
  • With the integrated display users can see the actual flow and the total consumption
  • IP65 casing provides robust protection in rough industrial environments
  • Isolated mA and pulse output signals or Modbus/RTU interface
  • Very fast response time, high accuracy and wide measuring range
  • Tube diameters of DN25 to DN500
  • 2 installation types: centre installation and 100 mm insertion depth installation for bigger pipes (> DN250)

Product enquiries


Suto iTec

We have partnered with Suto iTec to provide compressed air & gas measurement technology to Australia.

SUTO iTEC was born from an idea that compressed air and gas systems need improvement, that end-users were being starved of technology required to manage these systems and that the level of wasted energy needed to be brought under control. Since its inception in 2005, SUTO has grown to be one of the world leaders in compressed air and gas measurement technology and is the market leader in compressed air purity monitoring equipment.

More information about CAT Air and Suto iTec »

Our Suto iTec compressed air measurement technology product range