Pizza box not a lorry!

Flexible multi-position sensors offer wide range of measurement

The Rod Model RF Temposonics flexible multi-position sensor supplied by RDP Electronics is an extremely versatile sensor ideally suited for installation into cylinders for continuous operation in even the harshest industrial locations.

This sensor is notable for a measuring range of up to 20 metres and has the ability to measure non-linear paths such as around an arc up to 250mm bend radius, or even more complex shapes, so that it does not have to be fixed in a straight line to moving machine parts. Typical applications include measuring displacement of hydraulic cylinders.

It allows positioning of up to 20 magnets along the length of the sensor significantly reducing installation and maintenance costs associated with an alternative encoder, micro switch or proximity switch solution. The sensing element is contained in a coated stainless steel flexible housing and when required to do so, the sensor can be replaced in many cases without the need to remove the hydraulic cylinder. This is easier than for a typical non-contacting fitting where replacement usually means the cylinder has to be removed to allow sufficient space to withdraw the measurement sensor from the cylinder.

Thanks to the flexibility afforded by the Model RF, even with limited space behind the piston, a replacement can be fed into the hole in the sensor housing, which remains inside the hydraulic cylinder. The use of a pressure housing not only allows the sensor be replaced without removing the hydraulic cylinder, but very often the cylinder will not even need to the drained of oil as the pressure housing maintains the pressure containment while the sensor is replaced. The Model RF is offered with a measuring range from 100 mm to 20000 mm and output options include Analogue, SSI, CANBus, Profibus-DP and EtherCAT.

The flexibility of the design permits shipping of these very long displacement transducers in a compact package 1½m in diameter that looks more like a pizza box than requiring a very long lorry!