Radio Telemetry
It is sometimes necessary to transmit sensor data over a distance greater than the 100mm - 150mm range limitation of inductive coupling. Systems incorporating radio links using license free frequencies of 433MHz and 896MHz, and having a range of 10-100 metres are available. The transmitters employ similar signal conditioning, encoding circuitry and construction methods to that used in the rotary telemetry, ensuring excellent data quality and high reliability.
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16 Channel Strain Gauge System - Helicopter Blades
This system enabled transmission of 16 strain gauge signals in the frequency range DC - 1KHz from helicopter blades to receiving equipment housed in the cabin. The transmitter unit measures 140mm x 95mm diameter and incorporates re-chargeable batteries allowing 8 hours of continuous measurement.
16 Channel Thermocouple Temperature Measurement from Large Diesel Engine Piston
This system used 44MHz fm radio to collect data from the piston as inductive coupling cannot be used reliably inside a crankcase when large air-gaps are involved. Transmitter measures 80mm x 60mm x 8mm, weight 40 grams. Battery life 100 hours.
Torque Strain and Temperature Measurement from Wheel Hubs
It is sometimes more convenient to mount the telemetry transmitter on the outside of a wheel hub rather than inboard on the shaft. In this type of installation radio is used to transmit the data to a receiver inside the vehicle cab. The transmitter is powered by primary or re-chargeable cells. 3 Channel Transmitter: 1 Torque and 2 Temperature.
