FS 05

Calorimetric flow monitor

The calorimetric flow monitor FS 05 is based on the calorimetric measuring principle. It is a simple flow velocity sensor with one or two switching contacts. Due to this construction, it is intended primarily as the substitution of mechanical flow sensors in industrial cooling and building applications.

The flow velocity range of the sensor is 4 – 200 cm/sec. Contact making is indicated by means of two LEDs. The switching contact(s) is adjusted by means of the microswitch which has 16 positions. Electrical connection is provided by WAGO terminals on the PCB of the evaluation unit through the cable entry.

The electronic circuitry is always in compact construction with a secured high IP67 code. According to pipeline ID, there are two lengths of bar sensor, namely 65 mm (standard) and 125 mm. In case of an empty pipeline, the sensor behaves in the same way as in case of zero flow.


  • high reliability
  • long service life
  • signalization of contact making by means of LEDs
  • possibility of two switching positions
  • high IP code
  • utilisation in various flow sizes
  • electrical connection through the cable entry
  • continuous control of the sensor for correct operation


FLOWSWITCH 05 délka čidla 65mm


FLOWSWITCH 05 délka čidla 125mm


Power supply 24V±10%DC with polarity reversal protection
Input power 1,5/4 VA
Electrical connection cable connection via WAGO terminals
Process connection according to DIN2353 with the M16×1,5 union nut through the 24° ring into the direct socket with pipe thread (G1/2″; G1/4″; M14 × 1,5; NPT1/4″)
Sensor design compact
Display 4× LED
Types of ouputs reley
Contact rating 130 mA / 60 V / 500 mW
Response time * 1÷6 s
Velocity flow range 4÷200 cm/s
Accuracy ±2÷±8 cm/s
Hysteresis 2÷8 cm/s
Control microswitch (16 positions)
Temperature of liquid -10÷+80 °C
Ambient temperature -20÷+55 °C
Material in contact with medium stainless steel 1.4404
Maximum pressure 64 bar
Degree of protection IP67
Ambient humidity max. 90 %
Status contact SSR, passive, potential free, max. 350 V
AC/DC, 150 mA, 400 mW
Weight 290 g
Dimensions (H×W×D) 91×74×60 mm (in case of the longer version, the height is 151 mm)


Individual indications using LEDs:

  • supply voltage indicator
  • signalization of zero flow or lower than Qmin
  • SSR1 switching point value (indication during rotation of BCD SW)
  • SSR2 switching point value (indication during rotation of BCD SW)
  • signalization of SSR1 relay on-state
  • signalization of SSR2 relay on-state

The flow monitor includes two control buttons and a rotary microswitch (16 positions) by which means it is possible to set:

  • switching point/points for flow velocity (temperature in some case)
  • to modify the logics of the making/breaking output
  • to calibrate the minimum and maximum flow through the monitor
  • to reset factory default parameter values



In case when it is necessary to monitor the media flow in the pipe with a smaller DN than DN 25 (or the flow velocity is below the sensor range at the pipe diameter given), it is possible to use an adapter block with a corresponding flow velocity and ensure correct operation and keep the installation conditions in this way. The adapters are designed for a short version of the 65 mm sensor by using a direct neck with G½” pipe thread.

Individual designs:

  • FS adapter block DN20/G¾” for 1÷10 l/min. (size 150×50×40 mm)
  • FS adapter block DN15/G½” for 0,5÷5 l/min. (size 150×50×30 mm)
  • FS adapter block DN10/G¼” for 0,2÷2 l/min. (size 150×50×30 mm)
  • FS adapter block DN4,7/G¼” for 50÷500 ml/min. (size 70×50×30 mm)
  • FS adapter block DN2,7/G¼” for 2÷100 ml/min. (size 70×50×30 mm)