Gefran Expands GSH Series with Safety Certified Draw Wire Sensors for Mobile Machinery
The deployment of heavy equipment in harsh outdoor environments requires ruggedized sensing technologies capable of precise feedback under extreme operational stress. To meet the evolving demands of functional safety regulations in heavy industry, Gefran has expanded its high-performance GSH series of draw wire sensors to include models carrying comprehensive SIL2 and PLd safety certifications. These optoelectronic and magnetic displacement tracking devices provide essential linear and angular position tracking, serving as a critical hardware layer to prevent mechanical overextension, tip-overs, and structural failures in complex mobile applications. By ensuring compliance with modern international safety directives, the upgraded portfolio targets high-risk components such as telescopic crane booms, aerial work platforms, heavy-duty telehandlers, and specialized agricultural lifting systems.
Traditional linear displacement tracking methods in municipal or construction equipment often suffer from accelerated mechanical wear due to continuous exposure to environmental contaminants. Traditional draw wire units utilize wire-wound potentiometers that rely on physical wiping contact to measure changes in electrical resistance. The Gefran GSH architecture avoids this common point of failure by incorporating contactless Hall-effect sensing array technology inside the sealed transducer housing. Because the rotational speed and internal drum direction are calculated magnetically without physical contact, the internal sensing elements face zero friction-induced degradation. This non-contact approach significantly lowers lifecycle maintenance overhead and extends the operational longevity of the sensor, even when deployed on high-cycle material handling platforms or industrial machinery subject to persistent structural vibration.
The expanded hardware matrix is structured into two specialized product families to accommodate different machine kinematics. The GSH-S sub-series is optimized for straightforward linear displacement tracking, converting physical wire extension into precise longitudinal data. For more complex mechanical setups where an arm changes both its length and its relative working angle, the GSH-A variant provides simultaneous linear and angular tracking within a unified housing. Both families support versatile stroke configurations, providing continuous measurement spans starting at 1.8 meters for smaller compact tooling and extending up to 12.5 meters for large-scale agricultural and earthmoving machine structures.
Integrating these safety-critical units into existing vehicular electronic architectures is simplified through a wide array of industrial communication interfaces. For modern digital control topologies, the GSH sensors support native CANopen Safety protocols, enabling deterministic, redundant transmission of position data directly across the primary machine bus. For legacy control configurations or decentralized analog inputs, the units can be configured to deliver standard 0.5 V to 4.5 V linear voltage signals or resilient 4 mA to 20 mA current loops that resist signal attenuation over long cable runs. To safeguard electrical integrity against moisture ingress, high-pressure washdowns, and ambient grime, each sensor can be specified with heavy-duty automotive and industrial connectors rated up to IP67.
Achieving formal SIL2 and Performance Level d certification transforms these draw wire devices from standard measurement tools into verified components for risk-reduction architectures. The integrated safety electronics are engineered to facilitate continuous background diagnostics, enabling automated fault detection, internal failure logging, and the immediate execution of a predefined safe state if an operational anomaly occurs. This capability allows fleet engineers and B2B system integrators to build robust control architectures where sensor data directly feeds into automated interlocking sequences, safely mitigating field risks before minor component drifting can escalate into a catastrophic equipment failure.
Written by: Seth PriceSeth Price is an industrial instrumentation specialist with more than twelve years of expertise implementing robust feedback sensors, functional safety networks, and precision position control systems across the global heavy machinery and mobile automation sectors.