RDCL Digital Display Air Differential Pressure Transmitter RDCLDPSW
The RDCL Digital Display Air Differential Pressure Transmitter is a precision industrial pressure measurement instrument designed to monitor low air pressure, differential pressure and negative pressure in pipelines, ventilation ducts and industrial gas systems.
It operates using silicon piezoresistive sensing technology to provide accurate and reliable pressure measurements in industrial and environmental monitoring applications.
The transmitter features a digital LCD display, 4 to 20 mA analog output and a 12 to 30 V DC power supply for continuous pressure monitoring.
It supports a configurable measuring range covering negative 5 kPa to positive 5 kPa, with 0.5% full-scale accuracy for precise differential pressure measurement.
With optional RS485 Modbus RTU communication, the transmitter can be integrated with compatible PLC, SCADA and Building Management Systems for automated pressure monitoring and control.
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A. Product Overview
The RDCL Digital Display Air Differential Pressure Transmitter measures small pressure differences in air pipelines, HVAC ducts and compatible gas systems. Its silicon piezoresistive sensor converts pressure differences into an electrical signal for continuous monitoring.
The transmitter features an aluminum alloy housing and digital display for local readings. A standard two-wire 4 to 20 mA output enables integration with compatible PLC, DCS, SCADA and BMS equipment. Optional RS485 Modbus RTU communication is available. Applications include cleanrooms, ventilation, air filters, dust collection and boiler draft monitoring.
Key Features
Differential, gauge and negative air pressure measurement.
Selectable ranges covering -5 kPa to +5 kPa.
Silicon piezoresistive MEMS sensing technology.
Accuracy: 0.5% full scale.
LCD or LED display options; versions without display available.
Standard two-wire 4 to 20 mA output; optional RS485 Modbus RTU.
12 to 30 V DC supply, with 24 V DC recommended.
Aluminum alloy housing and compact construction.
Temperature compensation and damping filter for stable readings.
Adjustable zero and full-scale settings.
Long-term stability: ≤0.1% FS per year.
Overload capacity: 150% of rated range.
Suitable for industrial monitoring and automation.
Technical Specifications
Parameter | Specification |
|---|---|
Brand | RDCL |
Product Name | Digital Display Air Differential Pressure Transmitter |
Measurement Type | Air pressure and differential pressure |
Measurement Range | -5 kPa to +5 kPa, customizable |
Measuring Medium | Air and compatible non-corrosive, non-combustible gases |
Sensing Technology | Silicon piezoresistive MEMS sensor |
Accuracy | 0.5% full scale |
Standard Output | Two-wire 4 to 20 mA |
Optional Communication | RS485 Modbus RTU |
Display Options | LCD, LED or without display |
Power Supply | 12 to 30 V DC |
Recommended Supply | 24 V DC |
Housing Material | Aluminum alloy |
Long-Term Stability | ≤0.1% FS per year |
Overload Capacity | 150% of rated range |
Ambient Temperature | -20°C to 60°C |
Medium Temperature | -20°C to 60°C |
Electrical Connection | Direct cable outlet |
Pressure Connection | M8 tower connector or PC8-M6 quick-connect fitting |
Calibration Adjustment | Zero and full-scale adjustment |
Applications | HVAC, cleanrooms, air pipelines, filtration and automation |
Note: Range, display, output and connection depend on the selected version. Confirm the required configuration before ordering.
B. Working Principle
The transmitter compares pressures at its high and low ports. A silicon sensing diaphragm converts the difference into an electrical signal.
Differential pressure: ΔP = P₁ - P₂, where P₁ is high-side pressure and P₂ is low-side pressure.
Step 1: Air Pressure Detection
Air from a duct, pipeline or machine enters the high and low pressure connections. The device senses their difference. For suitable gauge measurements, one port may reference atmospheric pressure.
Step 2: Silicon Pressure Sensing
Applied differential pressure slightly deforms a silicon diaphragm, changing the resistance of its pressure-sensitive elements.
Step 3: Electrical Signal Generation
The sensing elements form a Wheatstone bridge that produces a voltage corresponding to differential pressure within the calibrated range.
Step 4: Signal Processing
Internal circuits amplify and linearize the signal, compensate for temperature and filter rapid fluctuations for stable measurement.
Step 5: Digital Pressure Display
The display version shows the measured pressure locally, allowing operators to check readings without a separate indicator.
Step 6: Industrial Signal Transmission
The two-wire analog version provides a 4 to 20 mA signal. Example for a linear range of 0 to 1 kPa:
Differential Pressure | Output Signal |
|---|---|
0 Pa | 4 mA |
250 Pa | 8 mA |
500 Pa | 12 mA |
750 Pa | 16 mA |
1000 Pa | 20 mA |
Compatible external controllers can use the signal for monitoring, alarms and programmed control.
Step 7: Continuous Pressure Monitoring
The transmitter continuously updates its readings and output as pressure changes, supporting ventilation, filtration and room-pressure supervision.
C. Why Is the RDCL Digital Display Air Differential Pressure Transmitter Used?
Small air-pressure differences indicate changes in airflow resistance, filter loading, room pressurization and ventilation performance. This transmitter enables local and remote monitoring.
1. HVAC Air Pressure Monitoring
Measures duct static pressure, AHU pressure, fan conditions and filter pressure drop. When connected to suitable controls, readings can support ventilation management and VFD operation.
2. Pharmaceutical Cleanroom Pressure Monitoring
Measures positive or negative pressure differences between cleanrooms, corridors and airlocks. Choose the range and accuracy according to facility requirements.
3. Industrial Air Pipeline Monitoring
Monitors low pressure and differential pressure in compatible gas pipelines, helping identify changing airflow, restrictions and operating conditions.
4. Industrial Air Filter Monitoring
Measures pressure drop across HVAC and industrial filters. Rising differential pressure under comparable airflow conditions may indicate filter blockage or a need for maintenance.
5. Dust Collection and Bag Filter Systems
Tracks pressure loss across dust-collection bag filters. Compatible controllers can use the signal to monitor filter loading or trigger cleaning sequences.
6. Boiler Draft Pressure Monitoring
Measures suitable low-pressure combustion air and furnace draft conditions. Verify gas composition and temperature against transmitter specifications.
7. Building Management Systems
Supplies pressure measurements to compatible BMS controllers for remote HVAC monitoring, ventilation control and alarms.
8. Laboratory and Controlled Environment Monitoring
Monitors low pressure differences between laboratories and adjacent controlled spaces to support facility pressure management.
9. Air Velocity and Flow Monitoring
With a suitable Pitot tube or primary flow device, the transmitter measures dynamic pressure. An external controller calculates air velocity using air density and the correct method.
10. Industrial Automation and Process Control
Provides pressure data to compatible PLC, DCS and SCADA systems for remote monitoring, process alarms and supervision of ventilation and filtration equipment.
D. Suitable Buyers
Suitable for industrial buyers, equipment manufacturers, HVAC professionals, automation engineers and maintenance teams requiring low-pressure measurement.
Buyer Category | Typical Applications |
|---|---|
HVAC Contractors | Duct and ventilation pressure monitoring |
Air Handling Unit Manufacturers | AHU filter and fan measurement |
Pharmaceutical Manufacturers | Cleanroom pressure monitoring |
Cleanroom Contractors | Room and airlock pressure monitoring |
Hospital Facility Teams | Controlled environment pressure monitoring |
Industrial Automation Companies | PLC and SCADA integration |
BMS Integrators | HVAC automation and monitoring |
Air Filter Manufacturers | Filter differential pressure monitoring |
Dust Collection System Manufacturers | Bag filter pressure monitoring |
Boiler Equipment Manufacturers | Combustion air and draft monitoring |
Laboratory Equipment Manufacturers | Low air pressure measurement |
Industrial Ventilation Contractors | Exhaust and ventilation monitoring |
Control Panel Manufacturers | Differential pressure monitoring panels |
OEM Machine Manufacturers | Integration into industrial equipment |
Engineering Procurement Companies | Industrial pressure instrumentation |
Industrial Maintenance Engineers | Filter maintenance and troubleshooting |
E. Frequently Asked Questions (FAQ)
Q1. What is the RDCL Digital Display Air Differential Pressure Transmitter?
An instrument for measuring small pressure differences between two air or gas points. It provides digital indication and an electrical signal for monitoring.
Q2. What is its measurement range?
The family offers selectable ranges covering -5 kPa to +5 kPa. Choose a range suitable for the application.
Q3. Does it support 4 to 20 mA output?
Yes. Its standard analog version uses a two-wire 4 to 20 mA output for compatible industrial controllers.
Q4. Does it have a digital display?
LCD and LED display versions are available, along with a version without display. Confirm the ordered type.
Q5. What power supply is required?
12 to 30 V DC, with 24 V DC recommended for industrial instrumentation.
Q6. What is its accuracy?
The specified accuracy is 0.5% of full scale.
Q7. Can it measure negative air pressure?
Yes, within the selected range, for compatible ventilation, room-pressure and draft applications.
Q8. Can it connect to a PLC?
Yes. The 4 to 20 mA signal connects to a suitable analog input. Optional RS485 can connect to compatible digital equipment.
Q9. Does it support RS485 Modbus RTU?
Yes. RS485 Modbus RTU is available as an optional configuration.
Q10. Can it be used in HVAC systems?
Yes. It can monitor pressure differences across compatible HVAC filters, ventilation ducts and air handling equipment.
