Modern day safety directives for machines, including on- and off-highway vehicles, require that correct hydraulic valve operation is assured. This means that spool valves often need to be fitted with sensors that can measure the actual valve position and feed this information back to the machine’s controlling electronics, which can then determine if the valve is in a safe position for the intended operation. Traditionally, these small-stroke linear sensors have been based around inductive technology but a more cost-effective approach is to use Hall-effect sensing, which is also non-contacting so can achieve equal levels of reliability.
The VPT351 can provide accurate, positional measurement over a span of 10-25mm and is designed specifically for the monitoring of hydraulic valves. The transducer can operate from either a 5V supply or an unregulated supply in the range of 9-32V, so making it suitable for vehicle applications.
A choice of output types is available: analog voltage in two spans, 0.5-4.5V or 0.2-4.8V; 4-20mA current loop; or one of three PWM frequencies. Each of the output types can have its full span set to correspond to the selected measurement range, while the polarity of the output is also configurable. The sensor and associated electronics are also shielded against electromagnetic disturbances.
Mounting to the valve block is via a standard M18 thread and an O-ring is fitted to ensure reliable sealing at operating pressures up to 420bar (5880psi), while being able to withstand periods of pressure as high as 600bar (8400psi).
Connection options are over-molded, industry-standard AMP Superseal or Deutsch DT04 series connectors, or simple flying leads for customer termination. Dependent on the type of connector used, sealing as high as IP69k can be achieved.
PDFs: CW-IG-OverviewBrochure.pdf vpt351_brochure.pdf vpt351_technical_information.pdf