New Railroad Sensor Aids Safety and Improves Maintenance Efficiency

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Product Innovation Ltd, a UK based innovation Company specializing in smart sensors, has announced a new product that measures the movement of a rail or railroad tie in real time. This increases safety and allows for maintenance crews to be called in only when needed.

Void Meter

The new concept is beautifully simple and uses modern electronics in a way that was not possible in the past.

Most people do not realize that, as a train passes, the rails themselves can deflect under the weight. The cause of this is the ballast (stones) under the ties shifting or settling over time. This is particularly important around points or crossovers or areas known for subsidence. In the past this has meant that railroad workers had to spot the movement and then call in a maintenance crew. But spotting a defect is difficult because it only shows itself as a train passes by.

Network Rail (NR), the huge UK rail infrastructure Company, were looking for a Void Meter to measure this movement and to fit in with their new Intelligent Infrastructure system. They approached Product Innovation having seen an old design on the Company's website. Once alerted to this interest Product Innovation reviewed the design and decided to produce a completely new one using the latest technology.

The new Void Meter was developed and a prototype built before the first meeting with NR. They were impressed by the design and ordered samples, the first of which was installed at Witham outside London in the UK in July 2014. Since then six more samples have been supplied. NR is investigating how best to use the devices, whether standalone or in combinations at points and crossovers etc. (Watch video of first prototype in action here).

The new Void Meter is simple to install, both physically and electrically, and provides a real time output in the form of a 4 - 20 milliamp signal. This is what NR requested. Other outputs are possible on request. It measures the vertical position of a tie or the rail itself and outputs the resulting signal continuously allowing for data loggers and direct remote reading to happen. The full range of position sensing is 4 inches which is sufficient to allow both upward and downward movement of a tie being monitored. The resolution is 0.02 inches. (1/50 inch)

The product is very robust as any product for the rail industry must be. All the mechanics and electronics are contained in a metal casting. Emerging from the casting is a moveable stainless steel rod which is sprung downwards towards the tie or rail. As the train passes and the rail moves, the steel rod follows it. The resulting position of the rod is measured within the casting itself and then converted to the 4 - 20mA signal.

Peter Frank, the CEO of Product Innovation says 'The new concept is beautifully simple and uses modern electronics in a way that was not possible in the past. The sensing of position uses a Hall Effect microchip (the Hall Effect is used in electronics to measure magnetism) that allows us to totally encapsulate the electronics. There is no physical connection at all between the mechanics that move the vertical rod and the electronics. This makes the product immune to the effects of weather and vibration. We believe this is a significant technological development and have applied for patents.'

The Void Meter will be of interest to any rail infrastructure company , all of whom are interested in safety and efficient maintenance.

About Product Innovation Ltd.
The London based Company has been developing sensors for Industry for more than 30 years. It has developed a wide range of products over the years including a new way to detect oil mist in marine diesel engines and a movement sensitive man down alarm for fire-fighters. Recent products include an optical sensor for measuring liquid refrigerant in large food stores and a consumer product that warns a BBQ user that the gas in the BBQ propane tank is running low.

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