The Siemens QBM68.1212 differential pressure sensor is designed for measuring differential pressure, positive pressure and negative pressure of air and non-corrosive gases. It features two independent measuring channels with a range of 0 to 1250 Pa and temperature compensation of both the zero point and sensitivity. The outputs are an analogue 0–10 V signal and a digital Modbus RTU bus, allowing the sensor to be easily integrated into building management systems (BMS/HVAC). Version without display, IP65 protection rating.

Key features

• Two independent measuring channels, each with a range of 0–1250 Pa
• Output signal: Modbus RTU and 0–10 V
• Power supply AC 24 V or DC 13.5–35 V
• Temperature compensation – current influence of ambient temperature on measurement accuracy
• Power consumption less than 1 VA
• Easy and quick installation, maintenance-free operation
• IP65 protection rating according to IEC 60529
• Version without display

Typical applications

• Measurement of differential pressure in ventilation and air-conditioning ducts (HVAC)
• Detection of positive pressure at the inlet opening for calculating volumetric air flow
• Monitoring and control of air flow
• Monitoring air filter contamination
• Control of fan speed and VAV systems