B4-Px LoRaWAN

Pressure monitoring devices

The B4 Px family of devices includes 4 devices for measuring differential pressure. Specifically, we have:

• B4 P1, with one differential pressure sensor.
• B4 P2, with two differential pressure sensors.
• B4 P3, with three differential pressure sensors
• B4 P4, with four differential pressure sensors.
• The pressure range for each input can be requested at the time of purchase, from 0 to 10 kPa to 0 to 500 kPa for the standard solution.
• Customized solutions with different pressure ranges are available upon request.
• Ideal for burners and thermal process monitoring.
• Sensor settings and calibration are accessible via the local web interface in configuration mode, with an automatic calibration algorithm.

The devices in the B4 Px series are equipped with LoRaWAN connectivity, with a transmission range of several thousand meters within the plant.

Differential pressure sensors (often also called differential pressure transmitters) are fundamental instruments in an industrial plant for measuring the difference between two pressures (P1 and P2) rather than the absolute or gauge pressure of a single point. This pressure difference (P1 - P2 = ΔP) provides crucial information for monitoring, controlling, and optimizing numerous processes.

Here are the main applications in an industrial plant:

Flow Measurement

• This is one of the most important applications. Differential pressure sensors are used in combination with primary flow elements such as orifice plates, Venturi tubes, or nozzles. When a fluid (liquid, gas, or steam) passes through a restriction, a pressure drop proportional to its flow rate is created.
• By measuring the pressure upstream and downstream of the restriction, the differential pressure sensor detects this drop and converts it into a signal indicating the fluid's flow rate.
• Examples. Measuring steam flow in a boiler, natural gas in a pipeline, cooling water in a circuit, compressed air in a system.

Monitoring of Filter Clogging or Efficiency

• Differential pressure sensors are installed upstream and downstream of a filter (air, oil, water, etc.).
• When a filter is clean, the pressure difference between the two sides is minimal. As the filter clogs with particles, resistance to flow increases, causing an increase in differential pressure.
• By monitoring this difference, it is possible to know when a filter needs to be cleaned or replaced, preventing system overloads, efficiency drops, or damage to downstream equipment.
• Examples: HVAC filters (heating, ventilation, and air conditioning systems), oil filters in engines or pumps, water filters, diesel particulate filters (DPF) on vehicles and industrial machinery.

Level Measurement in Closed Tanks

• In closed and pressurized tanks, level measurement can be complex. A differential pressure sensor can be used by measuring the pressure at two different vertical points within the tank (one near the bottom and one higher up).
• The hydrostatic pressure (due to the liquid column) between the two points varies based on the liquid level. The pressure difference is therefore proportional to the liquid height.
• Examples: Measuring liquid levels in storage tanks, pressurized reactors, steam boilers.

Pressure and Draft Control (e.g., in Furnaces, Boilers, Cleanrooms)

• To maintain a specific pressure or pressure differential between two environments.
• Furnaces and Boilers. Measuring the draft (negative pressure) in the combustion chamber or flue gas duct relative to atmospheric pressure. This is crucial for combustion efficiency and safety (preventing the escape of toxic fumes).
• Cleanrooms. Maintaining a positive pressure (overpressure) inside the room relative to the outside to prevent contaminants from entering, or a negative pressure (underpressure) in isolation environments (e.g., biological laboratories) to contain pathogens. Differential pressure sensors are essential for precise monitoring and control of these conditions.
• HVAC Systems. Maintaining the correct differential pressure in ducts to ensure adequate airflow and prevent energy inefficiencies.

Monitoring of Pumps and Compressors

• Detecting an increase in differential pressure across a pump or compressor can indicate an excessive load, clogging, or a malfunction.

Leak Detection

• In some systems, an unexpected drop in differential pressure can indicate a leak.

Simplified Principle of Operation

A differential pressure sensor has two input ports, each connected to a different point in the process where pressure is to be measured. Inside the sensor, a flexible membrane or diaphragm is placed between these two pressures.

The pressure difference between the two inputs causes the membrane to deflect, which in turn is converted into an electrical signal (often 4-20 mA or digital) proportional to the differential pressure.

In summary, differential pressure sensors are vital instruments for process control, safety, predictive maintenance, and energy efficiency in a wide range of industries, from power plants to chemical, food, pharmaceutical, and manufacturing.

The B4 Px family of devices allows pressure measurements to be taken at any point in the plant, thanks to LoRaWAN connectivity. Thanks to the IOThing platform, the detected data can be automatically analyzed and transformed into useful information.