
Level Ultrasonic Sensor: Working Principle, Types & Industrial Applications
Level Ultrasonic Sensor Overview A level ultrasonic sensor is a non-contact device used to measure liquid or solid levels...
Home » Products » Level Measuring Instruments » Displacer Level Gauge

The Displacer Level Gauge is a high-precision liquid level measurement instrument designed for industrial applications. Using the displacement principle, it accurately measures liquid levels in tanks, vessels, and process systems. Ideal for chemical, oil & gas, and pharmaceutical industries, this gauge ensures reliable and continuous monitoring even under high temperature, high pressure, and corrosive conditions. Available in stainless steel, explosion-proof, and OEM/ODM configurations, it offers flexibility for diverse industrial environments.
Level Measuring Instruments Description
Displacer Level Gauge-Features
Robust and Reliable Design: Simple structure ensures stable performance and minimal maintenance requirements.
Safe and Isolated Indicator: The liquid level indicator is fully separated from the measured medium, providing safe and reliable operation.
Wide Pressure Range: Operates under working pressures from -0.1 to 42 MPa, suitable for most industrial processes.
Extreme Temperature Capability: Works in temperatures from -60°C to +400°C, supporting high-temperature applications.
Accurate Measurement: Includes medium density correction and temperature compensation for precise level readings.
High Viscosity Compatibility: Capable of measuring liquids with viscosity up to 500 mPa·s.
Multiple Indicator Options: Available with M2 and M3 indicators for on-site display preferences.
Flexible Signal Outputs: Supports 4-20mA two-wire signals, switch outputs, and HART protocol, ideal for remote monitoring and process integration.


Displacement Level Gauge-Applications
The Displacer Level Gauge is designed for continuous liquid level and interface measurement in demanding industrial environments. As a factory-manufactured instrument, it is engineered to deliver stable and accurate performance under high temperature, high pressure, corrosive, and hazardous conditions.
It is widely applied in the following industries:
Oil & Gas Industry
Used for level and interface measurement in crude oil tanks, separators, and storage vessels, especially suitable for high-pressure and explosion-risk areas.
Chemical Processing
Ideal for measuring corrosive and toxic liquids in reactors, columns, and storage tanks, ensuring safe and reliable process control.
Power Generation
Commonly installed in boilers, feedwater systems, and condensate tanks for continuous liquid level monitoring.
Pharmaceutical Industry
Provides stable and hygienic level measurement in process vessels where accuracy and reliability are critical.
Food & Beverage Processing
Suitable for liquid level control in production and storage tanks, supporting consistent process operation.
Paper & Pulp Industry
Used for monitoring liquid levels in pulp processing and chemical dosing systems.
With a full metal structure, isolated indicator design, and multiple signal output options, the displacer level gauge is well suited for process control systems requiring long-term stability and low maintenance, making it a reliable choice for industrial liquid level measurement.
Buoyancy Level Gauge-Working Principle
The electric displacer level gauge measures liquid levels using the buoyancy principle combined with Hooke’s law. The displacer, suspended on a spring, responds to changes in liquid level: as the level rises or falls, the balance of buoyancy, gravity, and spring force shifts. This movement is transmitted through a magnetic coupling to an external indicator, providing a clear and accurate on-site reading.
Designed with a robust full-metal construction, the gauge keeps the indicator fully isolated from the measured medium, ensuring durability even in corrosive or high-temperature environments. It also offers flexible output options, including 4-20mA two-wire signals, switch outputs, and HART protocol, making it ideal for remote monitoring and seamless integration into industrial control systems.


Displacement Float Level Gauge-Indicator Function
M2 Indicator
The M2 is a square-type indicator. The vertical displacement of the displacer is transmitted through magnetic coupling and displayed on the pointer and dial, providing precise on-site liquid level readings.
M3 Explosion-Proof Indicator
The M3 is a prototype-type indicator designed for explosion-proof and intrinsically safe environments. It converts the displacer’s vertical movement into a readable value via magnetic coupling, displayed on the pointer and dial.
Explosion-Proof Rating: ExdⅡCT6Gb
Intrinsically Safe Rating: ExiallCT6Ga
The M3 indicator is ideal for hazardous areas, ensuring safe, accurate, and reliable level measurement in demanding industrial applications.
Level Measuring Instruments Parameter
| Measuring Range | 300-6000 mm (or according to user requirements) |
| Measurement Accuracy | 1.5, 2.0 |
| Buoy Material | 304, 316L, HC, Ti, etc.(Other special materials are negotiated for supply) |
| Medium Density | ≥0.45g / cm3 |
| Interface Measurement | The difference between the density of the two media is ≥0.1 g / cm3 |
| Medium Temperature | ≤80 ℃, ≤150 ℃, ≤250 ℃, ≤400 ℃ |
| Medium Pressure | standard type ≤4.0 MPa, pressure type ≤42MPa |
| Pressure Level | standard type: DN40-DN50 / PN4.0Mpa;DN80-DN100 / PN1.6MPa |
| High Pressure Type | DN40-DN50 / PN10.0MPa |
| Special Type | according to user requirements |
| Flange Standards | HG20592, DIN2501, ANSI, SH, GB (or according to user requirements) |
| Process Connection | flange DN50, G1.5 ”thread or according to user requirements |
| Output Signal | 4 ~ 20mADC (two-wire system) |
| Load Resistance | 500Ω (when 24VDC power supply) |
| Communication Output | HART, Modbus (RS485) |
| Alarm Output | upper and lower limit switch output |
| Contact Capacity | up to 400VAC 0.05A, 24VDC 0.2A |
| Working Power | 15-35VDC, 220VAC |
| Lithium Battery | 3.6V7.5HA, 220VAC |
| Ambient temperature | -20 ℃ ~ + 60 ℃ |
| Body Material | 304, 316L or user requirements |
| Display Case Material | standard type: cast aluminum, special type: 304, 316L |
| Protection Level | IP65 (IP68 negotiated supply) |
Instrava OEM/ODM
Instrava is focused on delivering reliable industrial solutions through carefully curated products, application-driven optimization, and flexible customization. We select proven instruments from trusted manufacturers to ensure consistent quality, optimize solutions based on real working conditions to solve practical challenges, and provide tailored configurations to meet specific application needs.
By combining selection expertise with application understanding, Instrava helps customers reduce risk, improve efficiency, and achieve dependable results in complex industrial environments.

How does a displacer level gauge measure liquid levels accurately?
The gauge operates on the buoyancy principle and Hooke’s law. The displacer’s movement in the liquid is transmitted through magnetic coupling to the external indicator, providing precise and reliable level readings.
Can it measure high-temperature or corrosive liquids?
Yes, with stainless steel or alloy construction, the gauge can operate in high-temperature liquids up to 400°C and handle corrosive chemicals, ensuring safe and durable performance in harsh industrial environments.
Is the gauge suitable for explosion-proof environments?
Yes, models with the M3 indicator are certified explosion-proof (ExdⅡCT6Gb) and intrinsically safe (ExiallCT6Ga), making them ideal for hazardous areas in chemical, oil, and gas industries.
What signal outputs are available for remote monitoring and process control?
The gauge supports 4-20mA two-wire output, switch signals, and HART protocol, allowing integration with DCS, PLC, and SCADA systems for real-time monitoring.
Can the gauge handle high-viscosity liquids?
Yes, it measures liquids with viscosities up to 500 mPa·s, including heavy oils, syrups, and slurry, without sacrificing accuracy or responsiveness.
Are custom OEM/ODM displacer level gauges available?
Yes, fully customizable solutions are available, including measurement ranges, materials, indicator types, and signal outputs, ensuring the gauge meets specific industrial process requirements.
Built on Consistency, Not Claims
We specialize in industrial analysis and detection, with a clear understanding of real-world operating environments and requirements.
Every instrument is evaluated based on performance, stability, and application suitability—not just specifications or pricing.
We work with trusted manufacturers to ensure stable supply, consistent quality, and dependable delivery.
Our recommendations are grounded in application understanding, helping customers avoid common issues and achieve reliable results.
Instrava is built to reduce uncertainty—so every decision you make is clearer, safer, and more reliable.

Level Ultrasonic Sensor Overview A level ultrasonic sensor is a non-contact device used to measure liquid or solid levels...
Modern warfare has shifted from traditional battlefield confrontations to precision strikes targeting industrial infrastructure, energy systems, and supply chain nodes....
When a conflict ends, rebuilding begins—not just cities, but systems. Energy, water, chemical production, and infrastructure must be restored quickly,...