Belimo 22ADP-154 Air Differential Pressure Sensor with Modbus, -100 to 2500 Pa

Overview

The Belimo 22ADP-154 is a differential pressure transmitter for air and other non-flammable, non-aggressive gases, designed for the monitoring tasks found in every air handling system. It measures overpressure, underpressure or differential pressure with a piezo element, offers eight selectable ranges between -100 and 2500 Pa, and delivers the result both as analogue voltage and over Modbus RTU. A second analogue output can be set to represent volumetric flow, so the same device can act as an airflow transmitter when combined with a pitot tube or flow probe. Belimo also offers the 22ADP-154L, identical in function but fitted with a backlit LCD.

Seven Star LLC supplies the Belimo 22ADP-154 on request to HVAC contractors, panel builders and building maintenance teams in Oman and the GCC, with engineering support in Muscat. A single multi-range part number reduces the number of sensor variants a facility has to keep for filters, fans and duct pressure points.

Measurement Principle

Two pressure ports on the side of the housing are connected by flexible tubing to the measuring points, for example upstream and downstream of a filter bank or across a fan. The pressure difference deflects the piezo measuring element, and the electronics convert the resulting signal into a calibrated reading in Pa or inches of water column. The Belimo 22ADP-154 is factory set to 0 to 2500 Pa, and a selector lets the installer choose ranges of 0 to 2000, 1500, 1000, 500, 250 or 100 Pa, or a bidirectional -100 to 100 Pa range for room pressurisation. Accuracy is ±5 Pa on ranges up to 500 Pa and ±10 Pa above that, with long-term stability of ±2.5 % of full scale over four years.

When volumetric flow is required, the Belimo 22ADP-154 applies the measured differential pressure from a flow probe to calculate airflow in m³/h, m³/s or cfm. The flow range is adjustable over Modbus, with a default of 0 to 750,000 m³/h. Response time can be set to 0.8 s for fast control loops or 4.0 s for a steadier signal in turbulent ducts. To keep low ranges accurate, Belimo specifies a manual zero-point calibration after commissioning and at intervals of 3 months for ranges up to 250 Pa, 6 months up to 500 Pa and 12 months above that.

Engineering Design of the Belimo 22ADP-154

The housing is UV-resistant polycarbonate with an NBR seal, rated IP65 and NEMA 4X, which allows installation on rooftop units and outdoor ductwork as well as in plant rooms. Wiring enters through a cable gland with strain relief and lands on pluggable spring-loaded terminals for conductors up to 2.5 mm². The device runs on AC 19 to 29 V or DC 15 to 35 V, drawing 4.3 VA on AC or 2.3 W on DC, and the sensing element withstands a burst pressure of 40 kPa. Ambient and media temperature limits are -10 to 50 °C.

The two voltage outputs of the Belimo 22ADP-154 are switchable between 0 to 5 V and 0 to 10 V. The Modbus RTU interface on RS-485 is set up with DIP switches for address, baud rate, parity and bus termination, and Belimo publishes a separate Modbus register document. Status LEDs show errors and bus traffic, and a push-button starts the zero-point calibration. For parametrisation beyond the defaults, the Belimo Duct Sensor Assistant App connects through the A-22G-A05 Bluetooth dongle. The sensor ships with a mounting plate and a duct connector kit with 2 m of PVC tube.

Key Features

The Belimo 22ADP-154 replaces several single-range transmitters with one configurable device:

• Eight selectable pressure ranges from -100 to 100 Pa up to 0 to 2500 Pa.
• Two analogue outputs, 0 to 5 V or 0 to 10 V, for pressure and volumetric flow.
• Modbus RTU communication with switchable bus termination.
• Accuracy of ±5 Pa on ranges up to 500 Pa and ±10 Pa above.
• Selectable response time of 0.8 s or 4.0 s.
• IP65 / NEMA 4X UV-resistant enclosure for indoor and outdoor ducts.
• Wide supply range of AC 19 to 29 V or DC 15 to 35 V.
• cULus approval and certification to IEC/EN 60730-1 and 60730-2-6.

Industrial Applications

Belimo names air filter monitoring, fan and V-belt monitoring, and fire and smoke control dampers as typical uses, and in Oman the filter duty is especially demanding: dust and sand load pre-filters on air handling units quickly, and a rising pressure drop is the earliest sign that fan energy is being wasted. The Belimo 22ADP-154 lets the BMS trigger filter changes on measured condition instead of fixed calendars in malls, hospitals, hotels and office towers in Muscat. Across a supply fan it confirms airflow after start-up, and with a pitot tube or EXT-AC airflow probe it measures duct air volume for fresh air verification.

The bidirectional -100 to 100 Pa range of the Belimo 22ADP-154 suits room pressure control in isolation rooms, clean rooms, laboratories and kitchens, where a small, stable pressure difference must be maintained between spaces. Seven Star LLC supplies the Belimo 22ADP-154 with pitot tubes, airflow probes and the Bluetooth dongle for projects in Muscat, Sohar and Salalah. Duct humidity and temperature are often measured on the same units with the Siemens QFM1660 duct sensor.

Dampers on these systems can be driven by the Belimo NM24A-SR damper actuator and Belimo LF24-SR spring-return actuator.

Technical Specifications

The data below for the Belimo 22ADP-154 is taken from the Belimo technical data sheet 22ADP-154.. (en-gb, 2024-04-25):

How to Order

To request a quotation for the Belimo 22ADP-154 or the 22ADP-154L display version, send Seven Star LLC the quantity, the application (filter, fan, room pressure or airflow), the required range and any pitot tubes or airflow probes needed. Our Muscat team will confirm the configuration against the Belimo data sheet, advise on stock and delivery in Oman and the GCC, and provide the technical data sheet with our offer. For process or low-range pressure duties, see also the Setra 264 low differential pressure transducer and the Dwyer MSX Magnesense transmitter.