Force measurement system for suspended helicopter loads
The HeliNav Loadmaster load sensor from British manufacturer Sensor Technology is based on strain gauges and can handle load measurements between 1 and 25 metric tons.
Its overload tolerance is up to 150 percent of the specified measurement range. The antennas integrated into the HeliNav Loadmaster allow it to transmit data to a matching touchscreen receiver on a license-free frequency band of 2.4 GHz over distances of up to 100 meters. Because the HeliNav Loadmaster is compensated for lateral forces, it allows precise measurements of swaying loads suspended from helicopters, cable cars, cranes, and other weighing apparatuses. The lateral force compensation ensures that the pendulum motion of the load does not alter the measurement. An aviation licensed version is available for use with helicopters.
The display on the receiver allows real-time readout of measurement data and saving measurement data of up to 280 hours on the integrated 32 MB storage device. Data can be transferred to a PC via the on-board USB interface for evaluation with Excel, LabView, or other analysis software. The battery in the sensor is also charged via USB or from an external power source with 5 to 28 VDC.
A typical application for the HeliNav Loadmaster in aviation is recording the loads that are suspended from a helicopter for transport. As the rates for helicopter flights are based on the payload, operators of transport helicopters can use the load sensor to quickly calculate the correct fees. Another application for load sensors in helicopter aviation are the testing scales used for determining a rescue helicopter’s center of gravity during the annual overhaul.
In addition, the sensor is suitable for a multitude of industrial applications for weighing and lifting, including in construction, manufacturing, and logistics. The direct read-out on the handheld terminal allows working without any wired connection to the load, which is particularly helpful in confined spaces such as on a theater stage. Thanks to the long range of the wireless connection, the operator can be positioned safely outside of the hazard zone of the load. Combined with a winch under tension, the HeliNav Loadmaster can be used to determine the stability of trees near roads or train tracks in order to assess the risk posed by extreme wind speeds.