Fischer DS21 ATEX Industrial DP Switch - thermal oil flow monitor

 Working Principle:

DS21 is based on rugged and uncomplicated diaphragm movement. It is suitable for overpressure, partial vacuum and differential pressure measurements.

The forces of springs on each side of diaphragm is balanced in a state of equilibrium. The applied pressure or differential pressure will creates an unbalanced force at the diaphragm. This force moves the diaphragm system against the force of the springs for the measuring range until a new equilibrium is reached. When subjected to excessive pressure, the diaphragm rests on metal supporting plates.

A centre-mounted tappet transfers the motion of the diaphragm system to the motion work and to the actuating elements of the microswitches.

Key Features:

• High sensitivity
• High repeatability of switching points
• Long service life
• Robust Design, over pressure protected

Key Specifications:

• Application: flow switch / control – Thermal oil DIN  32 727 orhot waterFlow 100
• Measuring range: 0 ~ 250 mbar to 0 ~ 6 bar
• Nominal pressure: 25 bar
• Max. static operating pressure: 6 ~ 16 bar
• Max. pressure load: one sided overpressure protected up to nominal pressure on (+) and (-) side of diaphragm, partial vacuum protected
• Accuracy: ± 2.5% of full scale
• Operating ambient temperature: -10° C to +70° C
• Operating media temperature: +70° C
• Protection class: IP54 acc. to DIN EN 60529
• Mounting: Vertical
• Zero adjustment: located on dial
• Contact output: 1 or 2 microswitches, 1-channel change-over contacts
• Pressure connection: Thread G 1/4 female, cutting ring connection for 6,8,10,12 mm diameter tube of brass, zinced steel or chrome nickel steel
• Measuring system: diaphragm, of reinforced Viton

Application areas:

• Thermal oil flow monitor and control
• Hot waterflow monitoring and control

Industrial areas:

• Building heating system
• Power plants, boiler application
• Clean room and laboratory rooms