When Terralogic Ltd, a provider of rugged computer solutions, wanted to source a linear encoder that could work in harsh outdoor conditions, the Cardiff-based company turned to the SHG-TT from Newall Measurement Systems.
Now, with a handful of rigs having undergone successful prototype evaluation by the customer, UK and worldwide roll-out looks almost certain to follow.
As part of the fisheries management programme, the Environment Agency, the public body responsible for protecting and improving the environment in England and Wales, wanted to improve its methods of fish measurement. The agency had been using conventional notebook logging methods for monitoring fish size within inland waterways.
“The Environment Agency approached us to provide an integrated method of recording fish measurement data,” explains Terralogic’s Managing Director, Ken Gray. “Their existing methods were both time consuming and open to misinterpretation.”
Terralogic proposed the provision of one of its ‘rugged’ tablet computers to allow the agency to undertake live data capture in the field and thus improve the lead-time and accuracy of its fish surveys. However, one dilemma confronting Terralogic was the necessity for a linear encoder with the ability to perform accurately and repeatedly in wet outdoor conditions. “We trawled the internet and caught sight of the SHG-TT from Newall,” says Mr Gray. “Having checked out its specification we thought it was right for the application.”
The latest SHG linear encoders are unique in that none of the electrical or measuring components are exposed to harsh environments, and will continue to provide accurate and reliable readings even when fully submerged in water or oil. For this reason the range carries an IP67 (NEMA 6) environmental rating.
These solid state devices use digital signal processors and high speed analogue-to-digital converters to provide rapid, accurate and repeatable positioning information. Newall SHG-TT linear encoders offer differential quadrature output at RS422 TTL levels. The units are modular – available up to 30m in length.
Having acquired its first SHG-TT, Terralogic set about incorporating the unit into the custom-designed fish measuring rig controlled by the company’s rugged computer. A trough is used to cradle the fish while a bar is moved manually to measure its length. A single button-push on the tablet computer’s touch screen is all that is required to record its length.
A Deva interface is used to link the SHG-TT linear encoder with Terralogic’s rugged computer.
Eight prototype rigs have now been supplied to the Environment Agency, which is currently performing a working evaluation of the product. Once the rig gets the final thumbs-up, Terralogic anticipates an extensive delivery programme incorporating the UK and the rest of the world.
