Optimised consumption of compressed air and predictive maintenance

The Sigma 420 Series

S420 flow / consumption sensor

The consumption sensor S420 is based on the thermal mass flow principle. It measures volumetric standard flow over a wide measuring range. The result is pressure and temperature independent. S420 is an in-line type sensor which is mounted into the pipe. There are 7 models available for ¼”, ½”, ¾”, 1” , 1 ¼”, 1 ½”, and 2” tubes. The version with display shows the actual volumetric flow and the total consumption. The consumption counter can be set via the keyboard. Various settings such as gas type, flow unit, reference standards, can be set ex factory or through our service kit. The service kit consists of a PC software and a interface box which connects the sensor to the USB port of the PC. Every sensor includes an analogue output (4…20mA) for flow and an isolated pulse output for the consumption counter.

 Features 

  • In-line type for high accuracy in small tube diameters.
  • Analogue output 4...20 mA, pulse output (galvanically separated).
  • Particular suitable for measuring process gases such as N2, Ar, He etc.
  • Thermal mass flow, independent of pressure and temperature changes
  • Easy installation
  • Very fast response time

Applications for Sigma 420

  • compressed air balancing
  • compressed air consumption measurement
  • leakage air / leak rate determination
  • mobile compressed air measurement in front of single machines / plants
  • flow measurement of process gases like e. g. nitrogen, CO2, oxygen, argon, nitrous oxide
  • flow measurement at nitrogen generators

Technical data

Sigma 420  Measured unit  m3/h, m3/min, l/min, cfm  

Accuracy  +- (2% of measured value + 0.3% full scale)  

Medium  Air,  non explosive gases (N2, O2, CO2, N2O, Ar)  

Operating temperature  -30 ... 80 ºC   

Operating pressure  Up to 16 bar  (optionally up to PN 40)

Analogue output  Signal: 4 ... 20 mA 

Scaling: 0 ... max range  

Pulse output  1 pulse per m3  

Power supply  24 VDC smoothed ± 15 %

PC connection: SDI interface

Mounting thread meas. section: R 1/4", R 1/2", R 3/4"R 1", R 1 1/4", R 1 1/2", R 2" external thread

Volumetric Flow Ranges

Inner tube  Measuring range
inch
dia (mm)
from to
1/4" 8.5 0.8 90 l/min
1/2" 16.1 0.2 90m3/h
3/4" 21.7 0.2 170 m3/h
1" 27.3 0.2 290 m3/h
1 1/4" 36.8 0.7 480 m3/h
1 1/2" 41.8 1.0 550 m3/h
2" 53.1 2.0 900 m3/h