SIEMENS Differential pressure switch QBM81-3 range 20 to 300 Pa

The pressure difference between the two pressure take-offs causes the deflection of the diaphragm connected to the spring. This special membrane ensures the long-term stability of the switching points. Each type of device has a scale for very precise setting of the switching point. The setting options are shown in the 5 diagrams in the "Functions" section. Differential pressure switches for air and non-corrosive gases, potential-free changeover contact AC 250 V, 5 (3) A.

• For ventilation and air conditioning equipment
• For monitoring air filters, air flow, fan operation
• For pressure monitoring in clean rooms, kitchens, etc.
• Simple assembly
• Switching cycle >1 mio
• Very precise setting
• Long-term stability

Differential pressure switches QBM81-... are used in ventilation and air conditioning equipment for:

• monitoring the pressure difference, underpressure and overpressure
• monitoring the condition of air filters and air flow
• detection of broken fan belts

Differential pressure switches can be used in clean rooms, kitchens, etc.

---

SIEMENS – Differential pressure switchs QBM81 - manual /en/