Fischer MS11 – Industrial Pressure switch for high demanding conditions

Fischer MS11 is rugged pressure switch for high demand working conditions which required vibration resistance, shock-resistant, working near breaking conditions. With Duratherm or NBR diaphragm, it can be used with any liquids and gaseous media, including aggressive media.

It consists of onboard indicator dial and 2 x adjustable setpoints changeover micro-switches.


Fischer MS11 – Pressure switch for high demanding industrial application – liquid, water, gas

pdf-imageRugged pressure switch for high demanding industrial conditions, vibration resistant, corrosion-free diaphragm, with indicator and adjustable micro-switches, for aggressive liquids, gases, waste water etc
Make: Fischer Messtechnik (Germany)
Model: MS11


Fischer MS11 is versatile, rugged and very robust designed pressure switch, ideally suited for high demanding conditions eg. pressure shocks, vibration, working near breaking capacity, thermal and geographical vibrations etc. The independent indication drive and switching function guarantee instrument’s high operation safety.

The pressure chamber and measuring diaphragm are available in different materials, suited to meet various working or operational requirements.

Fischer MS11 - corrosion, vibration resistant pressure switch for liquid, gas
Fischer MS11 – corrosion, vibration resistant pressure switch for liquid, gas


Working Principle:

Measuring system of MS11 is based on rugged, pressure sensitive but uncomplicated diaphragm movement. It is suitable for overpressure and partial vacuum pressure measurement.

In equilibrium state, the forces on springs on both sides of diaphragm are balanced. The measured pressure creates an unbalanced force on the diaphragm.

This force which moves the diaphragm system against force of the springs for measuring range until new equilibrium is achieved.
Diaphragm rest on metal supporting plates when excessive pressure is applied. A centre-mounted tappet transfers the motion of the diaphragm system to the indicator movement and to the initiating elements of the micro-switches.


Key Features:

  • 2 x change-over microswitches
  • High repeatability of micro-switches
  • Vibration resistant
  • Long service life
  • Rugged diaphragm system
  • Overpressure protected

Key Specifications:

  • Measuring range:
    • 0 ~ +400 mbar to 0 ~ +25 bar
    • -1 ~ 0 bar to -1 ~ +9 bar
  • Nominal pressure: 25 bar
  • Max. pressure: overpressure proof to nominal pressure (all measuring ranges), safe against negative pressure
  • Permissible ambient temperature: -10° C ~ +70° C
  • Permissible media temperature:  + 70° C
  • Protection class: IP54 per DIN EN 60529
  • Accuracy: ± 1.6% full scale
  • Output contacts: 1 or 2 micro-switches, 1-pole changing contacts, adjustable
  • Switching hysteresis: approx. 2.5% full scale
  • Electrical connection: cable terminal box
  • Pressure connection: connection shank G 1/2 B DIN EN 837
  • Measuring system:
    • for 16bar: reinforced elastomere diaphragm
    • for 0-25 bar: DURATHERM diaphragm
  • Pressure chamber: aluminium GkAlSi10 (Mg), varnished black; aluminium GkAlSi10 (Mg), HART-COAT; stainless steel 1.4305
  • Measuring diaphragm: diaphragm and gasket of NBR and viton; DURATHERM Ni Cr Co-alloy
  • Materials, wetted inner parts: stainless steel 1.4310, 1.4305
  • Approval: type examination according to the rules of “Germanischer lloyd” possible
  • Mounting : pipe, wall or panel


Industrial areas:

  • Process engineering
  • Environment engineering
  • Renewable energy eg. biogas etc
  • Waste Water Engineering
  • Effluent treatment
  • Breweries, alcohol industry