Constant monitoring of the water hardness

The Grünbeck hardness control measuring device softwatch

The hardness control measuring device softwatch is used to monitor the total hardness in the drinking water. The choice of the indicator determines the limit value.

Hardness control measuring device softwatch

This monitors the water hardness

The hardness control measuring device softwatch is for exclusive use in the industrial and commercial sector. The hardness control measuring device softwatch is designed to monitor one single soft water line. The hardness control measuring device softwatch is suitable for operation without constant supervision for monitoring steam boiler systems.

  • 1 x voltage-free input contact
  • 3 x voltage-free relay output for exceeding limit values, device malfunction, status message or lack of indicator

Application limits

Certain substances contained in the water can interfere with or falsify the colour reaction. Therefore, comply with the limit values below:

  • pH value 4 - 10
  • Acid capacity KS4.3 < 5 mmol/l
  • Iron (Fe) < 3 mg/l
  • Copper (Cu) < 0.2 mg/l
  • Aluminium (Al) < 0.1 mg/l
  • Manganese (Mn) < 0.2 mg/l


The installation location should be in the immediate vicinity downstream of a water softener to prevent a delayed response of the protective device or a falsification of the measured value.

Depending on the length of the supply line, the flushing time can be adjusted, so that the sampling water that is monitored during the measurement is always fresh.

The hardness control measuring device softwatch is installed in a branch of the soft water pipe and takes soft water samples at freely adjustable intervals. By adding an indicator to the water sample, a colour reaction is generated which is analysed by a sensor.

The interval period between two measurements is continuously adjustable:

  • Flushing time: 15 s – 1800 s
  • Interval period: 5 min – 360 min
  • Interval volume: 1 l – 9999 m³

In combination with a flow meter, a water meter or a water softener, the measurements can take place exactly when water is withdrawn. The indicator consumption can be optimally adjusted.