一、 Product Overview
The differential pressure transmitter (abbreviated as DP transmitter) is a high-precision industrial instrument used to measure the difference (ΔP) between two pressure points. It converts the differential pressure signal into a standard electrical signal (such as 4-20mA) for output, and is widely used in scenarios such as flow measurement, liquid level monitoring, and filtration system monitoring.
二、Core Features
| Characteristic | Description |
| High-precision measurement | The typical accuracy is ±0.075% – ±0.5% FS, suitable for precise control. |
| Wide range ratio | It can reach 100:1, meeting the needs of different working conditions. |
| Multiple output signals | 4-20mA + HART, RS485, PROFIBUS PA, FF, etc. |
| High pressure/high temperature resistance | Some models support a high pressure of 100MPa and a high temperature of 400℃. |
| Intelligent diagnosis | Self-checking, diaphragm health monitoring, fault alarm (intelligent type). |
| Multiple installation methods | Flange type, threaded type, bracket installation, etc. |
三、Working Principle
The differential pressure transmitter collects pressure signals through two pressure interfaces (high-pressure end HP and low-pressure end LP). The internal sensors (such as silicon piezoresistive, capacitive) calculate the differential pressure (ΔP = HP – LP) and convert it into a standard signal for output through an electronic module.
Typical measurement modes:
- Flow measurement (used with throttling devices such as orifice plates, V-cones, and venturis).
- Liquid level measurement (calculation of static pressure liquid level in open tanks/closed tanks).
- Filter monitoring (detection of filter screen blockage).
四、Product Series and Models
1. General Industrial Type
Applicable scenarios: Petroleum, chemical industry, power, water treatment, etc.
Features:
- Range: 0-1kPa to 0-40MPa.
- Material: 316L stainless steel, Hastelloy (corrosion-resistant).
- Protection level: IP67, explosion-proof option (Ex d/Ex ia).
2.Hygienic Type
Applicable scenarios: Food, pharmaceutical, dairy industries.
Features:
- Hygienic grade 316L stainless steel, electropolished (Ra≤0.8μm).
- Tri-Clamp, DIN flange connection, supporting CIP/SIP cleaning.
- Certifications: FDA, EHEDG, 3-A.
3. High Static Pressure Type
Applicable scenarios: High-pressure pipelines (such as oil and gas, boiler systems).
Features:
- Can withstand a static pressure of up to 42MPa.
- High stability, suitable for trade settlement.
4. Intelligent Type
Applicable scenarios: Internet of Things (IoT), digital factories.
Features:
- Supports wireless transmission (such as WirelessHART).
- Built-in AI diagnosis (predictive maintenance, drift compensation).
五、Technical Parameters
| Parameter | Specification |
| Measurement range | 0-100Pa~0-40MPa |
| Accuracy | ±0.075%~±0.5% FS |
| Output signal | 4-20mA + HART, RS485, PROFIBUS PA |
| Process connection | 1/4″ NPT, G1/2, flange (DN25~DN100) |
| Medium temperature | -40℃~+400℃ (high-temperature type optional) |
| Protection level | IP67/IP68 (submersible type optional) |
| Explosion-proof certification | ATEX, IECEx, CSA (optional) |
六、Typical Applications
- Petrochemical industry: Pipeline flow measurement (matching with orifice plates), fractionating tower liquid level control.
- Power industry: Boiler air pressure monitoring, steam flow of steam turbines.
- Water treatment: Filter tank differential pressure monitoring, liquid level measurement in pump stations.
- Pharmaceutical/food industry: Liquid level of sterile tanks, pressure monitoring of CIP systems.
- HVAC: Differential pressure of air conditioning air ducts, positive and negative pressure control of clean rooms.
