Pressure Sensors & Transmitters in Heavy Hydraulics, Aerospace & Injection Molding
High-performance pressure sensing is vital for controlling dynamic hydraulic power, ensuring flight-critical safety, and optimizing high-precision manufacturing. Heavy-duty pressure sensors and transmitters deliver precise, rapid-response continuous monitoring under extreme impulse pressures, severe shock vibrations, and extreme thermal environments.
Below is an overview of key application scenarios, technical challenges, and sensor selection guidelines across heavy industrial hydraulics, aerospace systems, and plastic injection molding machinery.
Core Applications & Operating Environments
1. Heavy Duty Hydraulic Machinery & Off-Highway Equipment
Heavy mobile hydraulics—including excavators, cranes, mining trucks, and hydraulic presses—rely on pressure sensors to manage load-sensing hydraulics and safeguard structural stability.
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Main System & Cylinder Line Pressure: Monitors real-time pressure in main hydraulic pumps and cylinder circuits to prevent mechanical overloads and smooth out motion control.
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Proportional Valve Feedback: Delivers high-speed pressure feedback to electro-hydraulic proportional valves for closed-loop dynamic position and force regulation.
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Key Demands: Resistance to severe hydraulic impulse shocks, extreme vibration immunity (20g – 50g), high burst pressure tolerance (4X to 5X FS), and IP67/IP69K ingress protection.
2. Aerospace & Aviation Systems
Flight control systems, landing gear hydraulics, engine fuel injection, and cabin environmental controls demand non-negotiable measurement accuracy and failsafe operational reliability.
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Flight Control & Brake Hydraulics: Monitors pressure in primary fly-by-wire hydraulic actuators and electro-hydraulic brake systems to guarantee instantaneous control response.
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Engine Fuel & Lubrication Monitoring: Tracks fuel line delivery pressure and jet engine lube oil pressure under aggressive thermal cycling and continuous high-frequency vibration.
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Key Demands: Ultra-lightweight packaging, extreme temperature range (-55ºC to +150ºC), DO-160G aerospace compliance, and high EMC/RFI shielding against electromagnetic interference.
3. Plastic Injection Molding Machinery
Injection molding machines require precise closed-loop pressure control across clamp units, injection cylinders, and hydraulic power units to eliminate product defects like flash or short shots.
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Injection & Hold Pressure Control: Measures hydraulic oil pressure in the injection cylinder during the fill and pack phases, maintaining accurate clamp tonnage and melt density.
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Hydraulic Accumulator Charging: Monitors pressure in nitrogen-charged hydraulic accumulators to ensure rapid injection speed capabilities.
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Key Demands: Ultra-fast dynamic response speed (< 0.5 ms), high long-term repeatability ( ≤±0.1% FS), and resistance to high-temperature hydraulic fluids (+125ºC).
Technical Performance Comparison Table
| Application |
Target Media |
Typical Pressure Range |
Crucial Technical Features |
| Heavy Mobile Hydraulics |
Mineral / Synthetic Hydraulic Oil |
0–250 bar / 0–600 bar |
Shock & vibration proof, IP69K, M12/AMP connectors |
| Aerospace Systems |
Skydrol, Jet Fuel, Aviation Oil |
0–200 bar / 0–350 bar |
DO-160 compliant, $-55^\circ\text{C}$ operation, hermetic seal |
| Injection Molding Machines |
Hydraulic Fluid |
0–160 bar / 0–400 bar |
Fast response ($<0.5 \text{ ms}$), high repeatability, CANopen |
| High-Pressure Hydraulic Presses |
Synthetic Hydraulic Oil |
0–700 bar / 0–1000 bar |
Ultra-high overpressure rating, sputtered thin-film core |
Technical Advantages of Heavy-Duty Pressure Transmitters
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Sputtered Thin-Film Sensor Technology: Sputtered thin-film on stainless steel diaphragms provides exceptional long-term stability, zero hysteresis, and high shock resistance without internal O-rings or organic adhesives.
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Integrated Impulse Dampening: Internal restrictor plugs protect the sensor element against severe pressure spikes and cavitation erosion caused by rapid hydraulic valve switching.
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Advanced Digital & Fieldbus Protocols: Supports standard analog signals (4-20mA ,0.5-4.5V), as well as CANopen, SAE J1939, and IO-Link for direct integration into machine controllers and vehicle CAN networks.
FAQ
Q: Why is micro-fused or sputtered thin-film technology preferred for heavy hydraulic applications?
A: Unlike bonded strain gauges or ceramic cores, sputtered thin-film sensors are molecularly bonded directly to the stainless steel diaphragm. This monolithic structure offers superior resistance to intense pressure spikes, high vibration, and thermal shocks without fatigue or fluid contamination risks.
Q: Can these pressure transmitters withstand Skydrol phosphate ester hydraulic fluids used in aviation?
A: Yes. For aerospace applications using Skydrol, wetted materials are custom-configured with specialized EPDM elastomeric seals or fully welded 17-4PH / 316L stainless steel constructions to ensure complete chemical compatibility.