Flush diaphragm pressure sensors engineered for tunnel boring machines. Measures earth pressure, grouting pressure and slurry in EPB shields — built to replace imported brands at a fraction of the cost.
- 316L SS
- 4-20mA
- IP67
- 0.2%FS、0.5%FS
- CE
Key Features－Engineered for the Harshest Underground Conditions
Tunnel boring machines operate in extreme environments — abrasive soil, corrosive slurry, constant vibration and high pressure. Every element of our TBM pressure sensor is designed to deliver reliable, real-time pressure data under these demanding conditions.
Flush Diaphragm Design
316L stainless steel flush membrane prevents clogging from sand, rock particles and viscous media. Hardened diaphragm resists abrasion for extended service life in earth pressure and slurry applications.
Anti-Vibration & Shock Resistant
Fully welded, all-stainless-steel construction withstands continuous mechanical vibration (20–1000 Hz, <0.1% FS output drift) from TBM cutterhead operations and thrust cylinder movement.
Wide Temperature Compensation
Operates reliably from -30°C to 85°C with active temperature compensation across 0–80°C. Stable output in fluctuating underground thermal conditions without recalibration.
High Accuracy Measurement
Combined accuracy of 0.25% FS or 0.5% FS using piezoresistive diffused silicon sensing elements. Delivers precise data to PLC control systems for real-time earth pressure balance monitoring.
Corrosion Resistant
Full 316L stainless steel wetted parts and hermetically sealed enclosure (IP67) resist corrosive slurry, acidic groundwater and chemical additives used in soil conditioning.
Drop-In Replacement
Matching mounting dimensions, thread sizes, output signals and pressure ranges of major imported brands. Reduces sensor procurement cost by 40–60% without system modification.
Technical Parameters
| Pressure Range | 0–6 / 10 / 16 / 25 / 40 / 60 / 100 bar |
| Accuracy | ±0.25% FS / ±0.5% FS / ±1.0% FS |
| Output Signal | 4-20mA (2-wire) · 0-5V / 1-5V / 0-10V (3-wire) |
| Supply Voltage | 24 VDC (10–36 VDC) |
| Overload Pressure | 150% FS (300% FS optional) |
| Burst Pressure | 300% FS |
| Response Time | ≤ 1 ms (10%–90%) |
| Long-term Stability | ≤ 0.1% FS / year |
| Diaphragm Material | 316L stainless steel |
| Housing Material | 304 / 304L stainless steel |
| Protection Rating | IP65 / IP67 |
| Media Temperature | -25°C to 85°C |
| Operating Temp. | -35°C to 85°C |
| Compensation Temp. | 0–50°C / -10–80°C |
| Electrical Connector | M12×1 plug · DIN 43650 · cable gland |
| Process Connection | G½ · M20×1.5 · custom thread |
Custom configurations available: Non-standard pressure ranges, HART/RS485 digital output, extended cable lengths, and brand-specific mounting adapters for Herrenknecht, Robbins, CRCC, and Komatsu TBMs.
Applications: Where Our TBM Pressure Sensors Are Used
From excavation chamber monitoring to backfill grouting control, our pressure transmitters serve every critical pressure measurement point on earth pressure balance and slurry shield TBMs.
- Earth Pressure Monitoring
- Installed on the bulkhead of EPB shield machines to continuously measure excavation chamber earth pressure, enabling operators to maintain face stability and prevent ground settlement.
- Grouting Pressure Control
- Monitors backfill and synchronous grouting pressure behind tunnel lining segments. Ensures uniform grout distribution to fill the annular gap and prevent surface subsidence.
- Slurry & Mud Pressure
- Measures bentonite slurry pressure in slurry shield TBMs. Flush diaphragm design prevents clogging from suspended particles, delivering accurate readings in high-viscosity media.
- Hydraulic System Monitoring
- Tracks thrust cylinder, articulation jack, and screw conveyor hydraulic pressure. Ensures TBM advance rate, steering accuracy, and muck discharge rate stay within optimal parameters.
- Foam & Conditioning System
- Monitors foam agent and polymer injection pressure in soil conditioning systems. Helps maintain the correct soil paste consistency for effective face support in EPB tunnelling.
- Pipe Jacking Machines
- Suitable for micro-tunnel and pipe jacking equipment where compact size, anti-clog properties and vibration resistance are equally critical for reliable pressure measurement.
TBM Pressure Sensor Working Principle
Tunnel boring machines (TBMs) typically employ strain gauge and piezoresistive earth pressure sensors. Piezoresistive sensors are widely used due to their high accuracy, stable output current, and low cost.
The core structure of the sensor includes: an electrical detection system assembly, a diaphragm, a connecting connector, a detection head mounting base, a detection head piston, and a sealing ring.
During operation, the soil in the soil chamber applies pressure to the piston, compressing the synthetic oil within the sealed chamber. This pressure causes a minute displacement on the diaphragm, thus changing its resistance. Ultimately, the pressure is converted into a current signal.
More Featured Pressure Sensors
FAQ
Why Leading Tunnel Contractors Choose Us
Sino-Inst has been manufacturing industrial pressure sensors for over 15 years. Our TBM-specific product line is trusted by tunnel construction teams worldwide.
Own Factory
In-house R&D, production, calibration and quality control. No middlemen — Better pricing.
Replacement
Pin-compatible with WIKA, Gefran, and other imported brands. Same performance, 40–60% less cost.
OEM & Custom
Custom thread, cable, range, output, and branding. MOQ as low as 10 units for project-specific needs.
Fast Delivery
Standard models ship in 3–5 days. Custom orders in 10–15 days. Expedited options for urgent projects.
Our TBM Pressure Sensors are compact, corrosion-resistant, vibration-resistant, resistant to hard sand impacts, and feature wide-range temperature compensation. Feel free to contact our sales engineers for customized solutions!