By Tony Kitazawa, Canon USA Optoelectronic Components
As sensing applications have become more advanced, demanding greater accuracy and device operability within increasingly challenging environments, contact-dependent sensing technologies and methods have failed to keep up. These methods’ inherent shortcomings have led organizations to seek non-contact sensing solutions but, even then, not all non-contact sensors offer equal value.
Contact-type measuring devices remain appropriate for some applications — namely, those not requiring a very high degree of precision — because in those cases a non-contact sensor would constitute an unnecessary expense. However, for many other applications, non-contact sensing is superior because it helps to prevent staining or damaging of objects during measurement, as well as avoids potential measuring errors within the device caused by slippage or friction.
Additionally, the accuracy of non-contact sensing is not impacted by sudden acceleration or slow-down — a significant concern during, for example, the stamping process when using a contact-type method due to the risk of slippage. Canon has taken non-contact sensing’s accuracy and utility a step further with the introduction of its PD-704 contactless measurement device, designed for high-precision measurements gauging the displacement and speed of target objects in a manufacturing environment.
The PD-704 boasts high acceleration tracking, supporting acceleration up to 100G. Bidirectional measurement and measurement under high-deceleration conditions also are supported. The PD-704 features a wide range of measurable speed (-4,000 to ~4,000 mm/s) complemented by an equally wide measurement depth, achieving ± 15 mm while working distance is 70 mm. Stable measurement is possible even if vertical vibration occurs (i.e., due to changes in speed) during inspection. Also, the PD-704 is capable of measuring target objects in a stationary state — a task impossible for traditional non-contact sensors.