Description
Fischer DS31 – adjustable DP Switch – water, sewage, gases
rugged differential pressure switch for water, liquids, gases, adjustable knob for set point
Make: Fischer Messtechnik (Germany)
Model: DS31
Fischer DS31 is rugged, industrial grade differential pressure switch for negative, positive and differential pressure monitoring. It is suitable for application for industrial water, water for chilling or heating system, neutral gases, oil etc.
DS31 is suitable for on/off control due to continuously adjustable switching point between 10% and 100% of the measuring range.

Working Principle:
DS31 works on rugged and uncomplicated diaphragm movement. It is suitable for monitoring positive, negative and differential pressure of water, industrial water, gases, oils etc.
The applied pressure creates an unbalanced force on the diaphragm, which move the diaphragm system against force of the range selector springs. A tappet, on mounted on diaphragm, actuates the microswitch.
The set point of the micro-switch can be adjusted by a scaled hand wheel / knob.
Key Features:
- Robust design, Maintenance-free
- High over pressure protection
- High repeatability of switches
- Easy, adjustable set point of micro-switches, via hand-knob
Key Specifications:
- Measuring range: 0 ~ 0.6 bar to 0 ~ 6 bar
- Max. static operating pressure: 16 bar (safe against positive and negative pressure)
- Pressure chamber: brass
- Permanent ambient & media temperature: + 80° C
- Diaphragm: NBR or Viton depending on usage
- Pressure connections: G 1/8 female cutting ring fitting for 6/8 mm tube
- Mounting: wall
- Protection class: IP65 acc. to DIN EN 60529
- Switching point: 10 ~ 100% of range, continuously adjustable, 250 VAC / 3 A
- Contact type: micro-switch, hysteresis approx 2%
Application areas:
- Roll band filter conditioning
- Pump monitoring
Industrial areas:
- Air conditioning plant and systems
- Ventilation systems
- Environment monitoring