Application of Pressure-Temperature Integrated Transmitters in Hydraulic System Monitoring

In modern industrial fields, hydraulic systems serve as the core power source for heavy machinery, providing strong and precise energy transmission for excavators, presses, injection molding machines, and other equipment. Pressure and temperature are the most direct indicators of hydraulic system health. With the advancement of Industry 4.0 and intelligent upgrades, pressure-temperature integrated transmitters have gradually become key components to improve system reliability and maintenance efficiency. The Nexisense pressure-temperature integrated transmitter, with highly integrated design and excellent environmental adaptability, brings significant changes to hydraulic system monitoring. This article analyzes its technical advantages, typical applications, and practical value, helping engineers and managers better understand this innovative solution.

Challenges in Hydraulic System Monitoring

Hydraulic system operating conditions are extremely complex: oil pulsation causes cyclic pressure shocks, pumps and motors generate continuous high-frequency vibrations, and solenoids frequently create strong electromagnetic interference. Additionally, high-temperature oil, metal particles, and chemical corrosion impose strict requirements on sensors.

Traditional solutions often use separate pressure transmitters and temperature sensors, leading to the following issues:

• Multiple installation ports increase potential leak points

• Signal acquisition is not synchronized, making pressure-temperature correlation inaccurate

• Complex wiring complicates troubleshooting and raises maintenance costs

• Large construction machinery often has limited space, making multi-sensor layout difficult

The Nexisense pressure-temperature integrated transmitter effectively addresses these pain points with an integrated design. A single process interface and one set of signal cables can output high-precision pressure and temperature data synchronously, simplifying system architecture and improving overall reliability.

Engineering Value of Integrated Design

Nexisense products use advanced glass microfusion technology, seamlessly embedding the pressure-sensitive element and temperature sensor within the elastomer, creating a fully welded structure without O-rings. This design eliminates the risk of leaks under high-pressure pulsation and temperature cycles.

Main performance parameters include:

• Pressure range: 0~40MPa (customizable for higher ranges)

• Temperature range: -40°C~+150°C (covers typical hydraulic oil operation)

• Combined accuracy: ±0.25% FS (higher accuracy optional)

• Output: 4-20mA + HART or Modbus RTU digital output

• Overload capability: 150%-300% FS; destructive pressure often >400%

This high integration saves space and improves data consistency—pressure and temperature signals are captured simultaneously, avoiding misjudgment caused by sampling delay, especially beneficial in dynamically changing hydraulic circuits.

Robust Environmental Adaptability

Hydraulic environments pose severe challenges for sensors. The Nexisense transmitter ensures long-term stability through multiple protections:

• 316L or higher stainless steel housing, resistant to oil corrosion

• IP67/IP69K protection, resistant to oil mist and high-pressure washing

• Built-in anti-vibration structure, withstands continuous 10g vibration (IEC 60068-2-6)

• Multi-level electromagnetic compatibility design, meets IEC 61000-4 standards, stable near solenoid valves

• Wide-temperature electronic compensation, ensures accuracy from -40°C~+85°C

These features make it ideal for installation at pump outlets, manifold interfaces, and accumulator connections.

Below are typical installation examples at hydraulic pump outlets or control valve blocks, showing integration with high-pressure pipelines and valve assemblies.

Typical Applications and Practical Benefits

Main Pump Monitoring in Construction Machinery

Installed at the main pump outlet of excavators or loaders, the Nexisense integrated transmitter monitors system pressure and oil temperature in real time. When temperature exceeds thresholds or pressure exhibits abnormal pulsation, warnings are triggered to prevent cavitation, bearing overheating, or accelerated oil aging. Manufacturers report a 25% reduction in hydraulic pump failures after adoption.

Manifold and Actuator Circuit Monitoring

Synchronous pressure-temperature data helps detect stuck valves, leaks, or oil viscosity changes. Temperature rise often indicates reduced viscosity and increased internal leakage, combined with pressure trends for early diagnosis.

High-Pressure Systems of Presses and Injection Molding Machines

High-pressure hydraulic systems are highly sensitive to overpressure and overheating. The integrated transmitter’s high overload capability and fast response (<2ms) provide reliable protection under extreme conditions, extending seals and pipeline life.

Seamless Integration with Smart Control Systems

Products supporting HART or Modbus can connect to PLC or SCADA systems for remote monitoring, trend analysis, and predictive maintenance. Some users integrate edge computing modules to predict oil replacement cycles and component lifespan from historical pressure-temperature curves.

FAQ

Does hydraulic oil temperature significantly affect pressure measurement?
Yes. Temperature changes affect oil viscosity and bulk modulus, impacting pressure transmission. Nexisense products have built-in temperature compensation to reduce cross-interference.

How to choose the appropriate range?
Recommend 1.5~2 times the maximum system pressure as the range, with sufficient overload margin. Nexisense supports custom ranges.

How to install in high-vibration conditions?
Prefer mounting near rigid bases with vibration-damping brackets. The transmitter’s inherent vibration resistance often requires no additional measures.

How does the maintenance cycle compare to traditional sensors?
Fewer connections and seals improve reliability; calibration interval can extend to 18-24 months depending on operating conditions.

Conclusion: Reliable Sensing for Hydraulic Systems

In modern high-load, high-speed, precision hydraulic systems, accurate and stable sensing directly affects equipment performance and lifespan. Nexisense pressure-temperature integrated transmitters combine high integration, robust protection, and intelligent output to quietly transform monitoring. It is not merely a measurement device but a reliable sentinel for system health management.

For applications with limited space, high reliability demands, or maintenance pressure, consider this integrated solution. It provides not only data but confidence and efficiency. Choosing Nexisense equips every unit of hydraulic power with the most trustworthy “sensor.” This technological advancement drives industrial equipment manufacturing toward higher reliability, lower energy consumption, and greater sustainability.