Axle Load Sensor — Datasheet

Overview

Overview

SGT Axle Load Sensor is a strain-gauge and air-bag pressure sensing kit for trucks, trailers and tippers that measures weight-on-wheel for every axle in real time and computes Gross Vehicle Weight (GVW) on the move. It replaces the once-a-day weighbridge ritual with continuous, audit-grade load data the driver sees before pulling away.

Overloading is the leading cause of premature chassis fatigue, brake failure and regulator fines in commercial transport. With sensors clamped to leaf springs or tapped into the suspension air-bag line, the system reads load every second, computes per-axle and total weights, flashes a cab warning before the truck moves, and writes a tamper-evident weigh-ticket to the cloud.

• Per-axle weight — strain-gauge or air-bag pressure on every axle
• GVW total + per-axle limits — fleet-specific policy, per-vehicle calibration
• Overload alarm in-cab — flashes before the driver releases the parking brake
• Weighbridge-free — audit-grade tickets stored in the cloud, no detour to a public scale

How It Works

1. Truck + Axles — strain-gauge transducers clamp to the leaf spring or pressure-tap into the air-bag line of each axle. Sensors are powered from the chassis 24 V bus and report over CAN-bus or RS-485 to the gateway.
2. Weight Calculation — the gateway reads the Wheatstone-bridge millivolt signal, applies the per-vehicle calibration curve, temperature-compensates, and produces axle weights with ±2% accuracy. GVW is the sum.
3. Compliance Cloud — every event (loading, departure, overload) writes a tamper-evident weigh-ticket with timestamp, GPS, photo (optional), per-axle weights and signature. Regulator-ready reports are exported on demand.
4. Driver / Loader — the driver sees a live load gauge in the cab; the warehouse loader sees the same data on a phone or yard display so they stop adding cargo before the limit is breached.

Features

• Strain-gauge or air-bag — choose per axle: strain on leaf-spring rigid axles, air-bag pressure on air-suspension axles
• ±2% accuracy — comparable to a static weighbridge after one-time calibration
• Temperature compensation — automatic correction for hot brakes / cold mornings, ±0.05%/°C drift
• In-cab display — color LCD with per-axle bars, GVW gauge, and overload buzzer
• Tamper-evident tickets — every weigh-event signed with device key, written to immutable cloud log
• Photo capture — optional yard-camera trigger on load-complete for proof of contents
• Loader app — yard-staff app shows live weight while loading, prevents accidental overload
• API + ERP integration — REST and webhook to your TMS / ERP so dispatch knows the load is legal before it leaves

Use Cases

• Bulk haulage — aggregates, cement, grain, where loading is by shovel and overload risk is highest
• Container drayage — confirming the manifest weight matches the actual axle distribution
• Logging / timber — variable density loads, no weighbridge near forest sites
• Tipper / construction — site-to-site moves where weighbridge access is impossible
• Regulator-mandated fleets — jurisdictions requiring on-board mass monitoring for B-double / road-train classes
• Self-billing & toll roads — automated GVW-based road-toll declaration

Specifications

• Sensor type: bonded foil strain-gauge (350 Ω full bridge) or 0–10 bar air-bag pressure transducer
• Range: 0–15 t per axle (configurable), 0–80 t GVW
• Accuracy: ±2% of full-scale after calibration, drift < 0.5%/yr
• Sampling: 100 Hz raw, 1 Hz reported, event-driven peak hold
• Gateway: 24 V automotive, CAN-bus, RS-485, 4G LTE, GNSS
• Cab display: 4.3" color LCD, sunlight-readable, IP54, with buzzer
• Environmental: sensors IP69K, gateway IP54, −40 to +85 °C operating
• Certifications: E-mark, OIML R134 (legal-for-trade option), FCC, CE, RoHS

Product information

Customisation options

• Sensor type per axle — strain-gauge on leaf-spring, air-bag pressure on air-suspension, or hybrid mix
• Axle count — 2-axle rigid up to 7-axle road-train, per-axle and per-axle-group reporting
• In-cab display — basic LED gauge, 4.3" color LCD, full 7" touchscreen, or driver-phone-only
• Calibration — one-time factory calibration, on-site weighbridge calibration, or self-calibrating reference load
• Accuracy tier — fleet-grade (±2%), audit-grade (±1%), or legal-for-trade OIML R134
• Connectivity — built-in 4G LTE, CAN-bus into existing FMS, or relay through ELD / tachograph head-unit
• Loader workflow — yard-display, loader phone app, dock-door TV, or integrated with your gate-pass system
• Ticket archive — SGT cloud, push to your ERP, export to regulator portal, or write to S3 / Azure Blob

Ordering & lead time

Standard lead time depends on current stock. For volume orders, please contact our team for a structured quote including BOQ, freight, installation and warranty terms.

Support

Engineering support, installation guidance and warranty claims are handled by our customer success team. Reach us at support@sgtsystems.com or via the channels listed on our Contact page.