Non-contact inductive linear sensors for harsh environments
Turck announced its Q-track family of linear position sensors has been expanded to include the newest QR14 and the Q17 models. Measuring just 14 mm and 17 mm in height, the compact, non-contact inductive sensors reportedly deliver repeatable measurements in applications with spacing limitations and harsh environments.
Turck’s linear inductive sensor operation is apparently based on the RLC resistance inductance capacitance principle. Unlike potentiometric or magnetostrictive technologies, the sensors incorporate precisely manufactured printed emitter and receiver coil systems. The emitter coils are activated with a high frequency ac field and produce an inductive RLC circuit with the positioning element. The element is inductively coupled with the receiver coils, which are arranged so different voltages are induced in the coils, depending on the position of the actuator. The voltages serve as a measure for the sensor signal. Q-track sensors deliver maximum measuring spans, with minimal blind zone and high resistance to EMI/RFI noise interference.
“The low-profile design and rugged housing make the Q-track sensors the preferred choice for versatile linear positioning applications,” said Marty Cwach, product manager, Turck. “Our ability to repackage technology into new housing designs enables us to deliver smaller sensors that suit the widest variety of application and spacing requirements.”
Q-track sensors reportedly eliminate common performance failures experienced with other technology options through linearity and familiarity. The RLC principle of operation used in the Q-track linear position sensor is highly immune to noise interference and is inherently weld field immune. Since the position element does not contain a magnet, it can be used in metal working applications because it will not attract ferrous debris, which would affect the operation of a magnetostrictive sensor. Additionally, the inductively coupled position element provides non-contact position feedback ideal for use in applications with constant motion, such as pinch rollers, cylinder position, web tension control, pitch control, resisting damage and costly downtime.
Along with their advanced design features, the sensors’ compact, durable construction increases functional flexibility. The QR14 and Q17 include current and voltage outputs, eliminating the need for two separate sensors and offering greater convenience and cost efficiency. The fully potted and sealed IP67-rated housing protects against moisture and dust in demanding environments.
– Edited by Chris Vavra, Control Engineering, www.controleng.com