Sensor Technology has set new performance standards for optical rotary torque transducers with its digital ORT 230/240 series. These transducers are ideal for applications requiring low torque and/or high bandwidth, offering precise, dynamic measurement of both rotary and static torque from 10mNm up to 100Nm, with bandwidths of up to 50kHz.

The ORT 230/240 devices benefit from advanced electronics that provide significant improvements in resolution, frequency response, reduced sensor current consumption, and faster digital data throughput. Their high-speed capability stems from the low inertia design, as the electronics are not attached to the shaft. Additionally, non-contact operation ensures long-term reliability and high accuracy, backed by Sensor Technology's lifetime warranty. The optical operating principle also delivers excellent noise immunity.

The ORT 230 series transducers offer fixed voltage or current analogue outputs – one for torque and one for either speed or power. Meanwhile, the ORT 240 provides two user-selectable voltage or current analogue outputs – one for torque and the other for speed, power, or peak torque. The ORT 240 also offers digital outputs, including RS232, CANbus, and USB, for easy interfacing with modern instruments and laptops. Users can connect up to 10 transducers via USB, and configure transducer variables using the accompanying software.

Both models include self-diagnostic features to alert users if torque, speed ratings, or calibration dates are exceeded. Built-in sensors monitor shaft temperature for improved compensation and accuracy, and there is a simple 'sensor status' output for added convenience.

These devices are complemented by Sensor Technology’s TorqView software, a user-friendly torque monitoring package for Windows PCs, enabling real-time data display and recording. TorqView supports real-time chart plotting and is compatible with both Matlab and Excel. For users who want to create custom process control applications, LabVIEW VIs are available, and DLLs are provided for those writing their own software.

These sensors significantly extend Sensor Technology’s torque monitoring range, offering an alternative solution when low torque or high bandwidth demands rule out the use of the TorqSense range.

Optical rotary torque sensors work by using a pair of gratings mounted a short distance apart on a strain-sensitive shaft to modulate a light source. As torque is applied to the shaft, a slight twist changes the alignment of the gratings, altering the amount of light transmitted to a detector. This method allows the sensor to measure torque bi-directionally, with fast mechanical and electrical response, low inertia, and no need for brushes or complex electronics.

The absence of brushes allows for high-speed operation, with a continuous rating of up to 30,000rpm as standard, and further increases in rpm are possible depending on shaft size. The torque shaft has low compliance, with a maximum torsion deflection of ½° on smaller transducers and ¼° on larger ones at full-scale deflection. Full-scale torque can be specified within the range of 10mNm to 100Nm.