1. Introduction
The FRD Sensor FD820C Embedded Micro Differential Pressure Transmitter is designed for low differential pressure measurement and embedded equipment integration, with a measurement range of 0–100 Pa to 2500 Pa.
With a compact design, 4–20 mA and RS485 + Relay outputs, and MODBUS RTU communication, FD820C is suitable for HVAC, cleanroom, air-handling and industrial automation applications.
2. Why Choose This Model?
Low differential pressure applications often face challenges such as detecting small pressure changes, limited installation space, measurement drift and system integration difficulties.
FD820C addresses these challenges with:
- Low Differential Pressure Measurement: 0–100 Pa to 2500 Pa
- Compact Design: Suitable for embedded equipment installation
- Stable Measurement: Accuracy of 0.5% F.S.; 1.0% F.S. optional
- Long-Term Stability: 0.2% F.S./Year
- Flexible Communication: RS485 and MODBUS RTU
- Multiple Outputs: 4–20 mA DC and RS485 + Relay
- Explosion-Proof Rating: Ex ia IIB T6 Ga
3. Model Comparison Table
| Parameter |
FRD Sensor FD820C |
Hon***ll P7650
|
Si****s QBM3235 |
| Product Type |
Embedded Micro Differential Pressure Transmitter |
Differential Pressure Sensor |
Differential Pressure Sensor |
| Measurement Range |
0–100 Pa to 2500 Pa |
25 Pa to 2500 Pa, model-dependent |
100 Pa to 3000 Pa, model-dependent |
| Pressure Type |
Differential Pressure |
Differential Pressure |
Differential Pressure |
| Overload Capacity |
2 × sensor range |
/ |
Model-dependent |
| Burst Pressure |
4 × sensor range |
Model-dependent |
Model-dependent |
| Accuracy |
0.5% F.S.; 1.0% F.S. optional |
Model-dependent |
<±0.6% F.S. |
| Long-Term Stability |
0.2% F.S./Year |
Model-dependent |
Model-dependent |
| Operating Temperature |
0°C to 60°C |
0°C to 60°C |
Model-dependent |
| Power Supply |
16–32 VDC |
12–30 VDC |
Model-dependent |
| Output Signal |
4–20 mA DC / RS485 + Relay |
4–20 mA / 0–5 V / 0–10 V |
4–20 mA / 0–10 V |
| Communication Protocol |
MODBUS RTU |
Model-dependent |
Model-dependent |
| Explosion-Proof Rating |
Ex ia IIB T6 Ga |
— |
— |
| Typical Applications |
HVAC, Cleanrooms, Industrial Automation |
HVAC, Airflow & Building Systems |
HVAC & Air Handling Systems |
| Warranty Period |
12 Months |
— |
— |
-
| Parameter |
FD820C |
| Range |
0-100Pa~2500Pa |
| Pressure Type |
Differential Pressure |
| Overload Capacity |
Allows overload pressure 2 times and destroys pressure 4 times the sensor range |
| Accuracy |
0.5%F.S; 1.0%F.S(optional) |
| Long Term Stability |
0.2%F.S/Year |
| Operating Temperature |
0℃~60℃ |
| Power Supply |
16V~32VDC |
| Output Signal |
4mA~20mA DC,RS485+Relay |
| Protocol |
MODBUS RTU |
| Explosion-Proof |
Ex ia IIB T6 Ga |
| Ambient Temperature |
Stainless Steel |
| Warranty Period |
12 months |
4. FRD Sensor FD820C OEM & ODM Customization Services
FRD Sensor provides flexible OEM & ODM customization services for FD820C to meet the micro differential pressure measurement requirements of equipment manufacturers and system integrators.
Customization options include:
- Measurement range
- Accuracy level
- Output signal
- RS485 / MODBUS RTU communication
- Electrical interface
- Mounting configuration
- Housing configuration
- OEM labeling
These options support efficient integration into HVAC, cleanroom, air-handling and industrial automation systems.
5. FRD Sensor FD820C Embedded Micro Differential Pressure Transmitter Measurement Accuracy Troubleshooting Guide
When FD820C shows abnormal readings or measurement deviation, follow these steps:
- Step 1: Check the Power Supply
Verify that the supply voltage is stable and within the specified 16–32 VDC range.
- Step 2: Check the Pressure Connections
Inspect the positive and negative pressure ports and tubing for leakage, blockage or incorrect installation.
- Step 3: Check the Zero Point
Verify the zero output under zero differential pressure conditions.
- Step 4: Check the Output Signal
Confirm that the 4–20 mA output and RS485 data correspond correctly to the actual differential pressure.
- Step 5: Check MODBUS RTU Parameters
Verify the communication address, baud rate and other communication settings.
If the problem persists, contact FRD Sensor for technical support.
6. Application Scenarios
7. Product Certifications
8. Packing
9.Conclusion
The FRD Sensor FD820C Embedded Micro Differential Pressure Transmitter combines a compact design, low differential pressure measurement, stable accuracy, RS485 communication and MODBUS RTU protocol, providing a reliable solution for HVAC, cleanroom, air-handling and industrial automation applications.
