Posted to News on 15th May 2009, 10:50
Low-cost cable extension sensor is user-configurable
Variohm EuroSensor is launching a new low-cost cable extension 'string-pot' position sensor featuring a user-programmable measuring range if up to 3175mm, a user-selectable output voltage, and a durable construction that is suitable for use in industrial wet environments and challenging outdoor applications.
Known as the SR1V, from USA company Celesco Inc, the sensor also features mounting flexibility, with its integral mounting bracket and moveable rear cover facilitating many alternative positions for the measuring cable exit and integral electrical connection. In all, the electrical and mechanical flexibility allows for a single product to be specified across many applications for draw-wire or string-pot-type position sensing, thereby eliminating the need to specify and purchase multiple stroke ranges - which provides benefits of simplified inventory and lower unit cost.
The SR1V is factory programmed for its full range of 0-3175mm with a 0-10V DC and 4-20mA outputs. Reprogramming the SR1V is easily carried out in situ and involves only the removal of the rear cover and adjusting the zero and span pushbuttons, which are located on a digital controller board, in combination with extending the measuring cable between the required positions. Within the full mechanical range, the user can select and guarantee optimum voltage output over any range. Furthermore, the output voltage can be adjusted and its polarity reversed using four signal selection dip-switches on the controller board covering selectable ranges of 0 to 5, -5 to +5, 0 to 10 and -10 to +10V DC and 4-20mA.
A 15-30V DC supply with 50mA current powers the unit with electrical connection via a four-pin M12 connector, which is supplied complete with mating half. A 4m cordset with a fitted M12 connector is available as an option.
Fully protected
Protected to IP67 for dust and water immersion, the SR1V also has a ruggedised polycarbonate housing that helps to ensure an operating temperature range of -40degC to +85degC. Installation is straightforward, with no critical alignment required. The spring-loaded and nylon-coated stainless steel cable is easily attached to the object under motion and fully retracts into the body of the SR1V, requiring a compact installation envelope within 200x120x100mm (wxhxd).
This plastic-hybrid precision potentiometer returns a rated life of 250,000 cycles, and an output signal update rate of 1msec ensures fast response for a maximum linear velocity of 2m/s and acceleration to 10 'g' on retraction. Positional accuracy is specified at 0.5 per cent FS with repeatability to 0.1 per cent FS.
Originally designed as an OEM product for off-road construction equipment, the SR1V's durable and flexible construction suits applications in agricultural machinery, water and waste treatment, and processing equipment requiring washdown. As a low-cost position sensor with a true one-size-fits-all capability, the SR1V will also interest general-purpose users and OEMs across all industries.
