Differential Pressure Transmitters Explained
Differential pressure measurement provides a reliable way to monitor the difference in pressure between two points in an industrial process application. OleumTech Differential Pressure Transmitters deliver accurate, repeatable DP measurement for flow, liquid level, equipment monitoring, and other demanding industrial applications.
What is Differential Pressure Measurement?
Differential pressure is the difference in pressure values between two defined points within a system or process. It is expressed as ΔP = P₁ − P₂, where P₁ represents the pressure at the first measurement and P₂ the pressure at the second measurement. Differential pressure measurement is the process of measuring and monitoring this pressure difference to evaluate changing conditions within a process or across equipment.
In industrial applications, differential pressure measurement can be used to determine flow rate, measure liquid level in pressurized vessels, monitor filter condition, and detect pressure loss across process equipment. A differential pressure transmitter provides continuous measurement of this pressure difference, allowing the resulting data to be used for process monitoring and control.
How Do Differential Pressure Transmitters Work?
A differential pressure (DP) transmitter measures the difference in pressure between two points within a process. The high-pressure port (P₁) connects to the higher-pressure side of the process, while the low-pressure port (P₂) connects to the lower-pressure side. The transmitter has an internal sensing element, such as a diaphragm, that reacts to the pressure difference between the two sides.
If the pressure at P₁ increases relative to P₂, the diaphragm deflects in one direction. If the pressure at P₂ increases relative to P₁, it deflects in the opposite direction. The transmitter detects this response and converts it into an output signal that corresponds to the measured differential pressure. This allows differential pressure measurement data to be transmitted to a PLC, RTU, or SCADA system.
Advantages of DP Transmitters
- Versatile Process Measurement: Differential pressure transmitters can be used for flow measurement, liquid level measurement, filter monitoring, and detecting pressure loss across process equipment.
- Accurate, Continuous Monitoring: DP transmitters provide continuous measurement of pressure differences, helping operators identify changing process conditions and equipment performance.
- Liquid and Gas Applications: Differential pressure measurement is suitable for a wide range of liquid and gas process applications.
- Remote Process Monitoring: DP measurement data can be transmitted to centralized monitoring and control systems, reducing the need for manual field readings.
- Control System Integration: Multiple output and communication options enable integration with PLCs, RTUs, DCS, SCADA systems, and other industrial automation equipment.
- Reliable Industrial Performance: Rugged DP transmitters provide dependable measurement in harsh environments and demanding process conditions.
Common Differential Pressure (DP) Measurement Applications
DP transmitters provide accurate differential pressure measurement across a wide range of process conditions, supporting common oil and gas and industrial applications including flow, level, and equipment monitoring.
Differential Pressure Transmitters for Level Measurement
Differential Pressure (DP) Flow Measurement
Differential Pressure Measurement for Heat Exchangers
Featured Products
As a differential pressure transmitter manufacturer, OleumTech provides accurate and reliable DP measurement solutions designed for flow, level, equipment monitoring, and other demanding industrial applications.
HDPTxxxx
Differential Pressure Transmitter
PRODUCT HIGHLIGHTS:
- Pressure type: differential pressure
- Multiple measurement ranges from
-435 to 1500 PSI (-12041 to 41520 inH2O) - Reference accuracy: ± 0.075% of full span
- Stability: ± 0.2 % Upper Range Limit / 5 years
- Output signal options:
(1) 1-5 V (2) RS485 Modbus
(3) 4-20 mA (4) 4-20 mA/HART - TD ratio of up to 100:1 (accuracy not affected at TD ratio of 10:1 and below)1
- All models support PV reversal (high side / low side)
except for the 1500 PSI model - Backlit LCD provided with both internal
and external control buttons - Diaphragm option: Hastelloy C or 316L SS
- 2X overload pressure using dual diaphragm structure
- HART support:
– Universal and Common Practice Commands supported
– Compatible with most HART Field Communicators - Operating temperature:
-40 to 60 °C (-40 to 140 °F)
LCD: -20 to 60 °C (-4 to 140 °F) - Dual seal certified per CSA C22.2 No. 30-20
- Accurate filling fluid technology eliminates effects of temperature and static pressure
- Process temp. measurement tag supported on Modbus and HART, -40 to 85 °C (-40 to 185 °F)2
- Explosion-proof (standard on all models)
- Intrinsically Safe (4-20 mA/HART options only)
- NACE MR0175 Compliant
- Mounting Kit Available
Differential Pressure Measurement FAQs
What is a differential pressure transmitter?
A differential pressure transmitter, or DP transmitter, is an instrument that measures the pressure difference between two points. By comparing the high-pressure and low-pressure sides of the sensor, it provides an accurate differential pressure measurement for applications including flow measurement, level measurement, filter monitoring, and process control.
How does a differential pressure transmitter work?
A differential pressure transmitter measures the difference between two points using separate high-pressure and low-pressure ports. The pressure difference causes an internal sensing element, such as a diaphragm, to deflect. The transmitter detects this response and converts it into an output signal that corresponds to the measured differential pressure for process monitoring and control.
What is differential pressure?
Differential pressure is the difference in pressure between two separate points within a process. It is calculated by subtracting the pressure at one measurement point from the pressure at another (ΔP = P₁ − P₂).
What is differential pressure measurement used for?
Differential pressure measurements provide valuable information about process conditions. DP measurements are commonly used to calculate flow, determine liquid level in pressurized vessels, monitor filter performance, and identify pressure losses across piping and process equipment.
How is differential pressure used to measure flow?
Differential pressure can be used to determine flow rate by measuring the pressure drop across a primary flow element, such as an orifice plate, venturi tube, or wedge meter. As fluid passes through the restriction, a pressure difference is created between the two sides. The measured differential pressure can then be used to calculate flow rate for process monitoring and control.
How is differential pressure used to measure level?
DP Level Measurement technology utilizes pressure readings and a fluid’s liquid density, or Specific Gravity (SG), to determine and output its level. By measuring the head pressure (high side) and gas/vapor pressure (low side) difference between two points, DP transmitters can accurately determine liquid level while providing reliable performance in demanding industrial environments.