Pressure transducers for railway applications
12 March 2013
Pressure sensors specified for railway applications require a particularly focused approach in both development and manufacture.
Applications range from monitoring brake servo control circuits through to air conditioning controls inside carriages. Common requirements across all applications are durability and robustness in design, higher and tighter specification requirements as well as the need for elevated levels of reliability.
These transducers include advanced specifications such as EN 61373 and DIN EN60068-2-27 for shock and vibration, and EMC sensitivity protection to EN50155 and EN50121. Furthermore, fire grade protection to class UL94 and ingress protection ratings to IP69K are commonly required, along with dielectric strength to over 700 VDC for one minute. Using advanced FIT rate analysis, an MTBF life of over 480 years was determined for one particular application.
The SML 16.0 series from Variohm EuroSystem's German manufacturing partner ADZ – Nagano has been designed for such requirements and application conditions. This pressure transmitter is suitable for working in ambient temperatures ranging between 50…105°C, with a precision of <1% F.S. in the range between 40…85°C (in accordance with DIN 16086).
The SML series transducers are for use in typical industrial pressure applications from 1.6 to 60 bar, whilst the entire SML family can cover up to 2000 bar. This complete range features a wide choice of interconnecting threads, electrical connections and signal output options for flexibility in interfacing.
Variohm supplies a comprehensive range of pressure sensing products including a new combined pressure and temperature sensor as part of its EPT pressure transducer family, as well as pressure switches and dedicated HVAC sensors which may offer a lower cost solution for refrigeration, automotive and other demanding markets.
A new economically priced cylindrical style sensor has recently been launched that features a piezoresistive ratiometric output measuring cell in a lightweight and durable injection moulded ABS plastic housing for pressure ranges to 20 bar.
Variohm EuroSensor will be exhibiting at this year’s RAILTEX 2013 - Stand J56.