Application Note: ADZ SMD series differential pressure transmitter for very long railway train braking applications

Variohm EuroSensor: ADZ NAGANO GmbH develops and manufactures pressure sensors and transmitters that meet the highest industrial requirements for standard and specialist applications ranging from mobile machinery to aerospace equipment. Represented in the UK by Variohm EuroSensor, ADZ is especially active in technologically demanding projects such as the following railway braking application that call upon its considerable expertise to solve unusually challenging tasks.

On very long railway trains, the multiple locomotives positioned at the beginning and in the middle and probably at the end of a train, usually communicate via radio. Commands for braking or accelerating, for instance, are transmitted in that way. However, in difficult terrain such as in the mountains or in tunnels, communication may be interrupted or not sufficiently reliable. This may result in severe problems. A back-end train segment, for example, that is not braked or whose speed in a bend is too high, involves a risk of accident that must not be underestimated.

Remedial help can be provided by ADZ’s SMD Differential Pressure Sensor, which measures the flowrate in the braking system. The values will determine whether a signal for braking or for releasing the brakes is required. The locomotive in middle position or at the end of the train, which then has no radio link, receives this information and initiates braking or loosening the brakes for the respective train segment.

The sensors are additionally used to make sure prior to departure from a station that the brake system is completely tight and has no leak. The proof that such a test is performed before leaving a station and the measured data recorded is statutorily required in Canada and the US, for example.

The sensor must withstand typical rail requirements with a view to prevailing temperatures, vibrations and electromagnetic compatibility (EMC). This in turn requires the sensors neither to be interfered by mobile phone signals or other radio sources nor to influence them.

The sensor design is custom-made, individually fitting the respective requirements regarding the available space, necessary connecting configurations or electrical contacts.

Variohm EuroSensor represents the comprehensive ADZ product range with technical support and service plus stock delivery available for many standard pressure sensors. The leading sensor and transducer manufacturer, distributor and supply chain partner also provides a custom design and modification capability for specialist sensor applications with full integration with other Variohm sensor technologies.

About Variohm EuroSensor

Variohm EuroSensor is a manufacturer, distributor and supply chain partner providing complete sales and application support across a comprehensive range of position, force, pressure, load, and temperature sensor technologies - for demanding measurement applications across industry, construction, agriculture, motorsports, research and more.