Thread detection plays a crucial role in mechanical production – especially in automated assembly or testing processes. Whether the thread is present, correctly executed or positioned correctly can determine the functionality of a component.
This task requires sensors that can reliably detect the smallest structures and at the same time precisely distinguish between shiny, dark or differently shaped surfaces. Reflex sensors with background suppression from wenglor offer a robust and economical solution for this. They detect fine structures such as external threads without contact and with process reliability, even in compact installation situations.
Thread detection involves detecting the smallest geometric differences in the range of a few millimetres. Smooth or matt surfaces, dark coatings or inclined threads are classic challenges for optical systems.
The P1MH202 reflex sensor works with a focused laser beam and intelligent background suppression. This technology is based on the principle of triangulation: the sensor measures the distance via the angle of the reflected light signal and can therefore separate foreground objects – such as the thread – from background structures in a targeted manner. This makes it possible to detect even filigree thread contours without reflections or shiny spots distorting the measurement result. In practice, threads up to size M6 are reliably detected, even on dark or coated surfaces.
The P1MH202 is designed in a compact standard housing from the PNG//smart series and can be easily integrated into automated testing systems. The sensor can be parameterized, read out and integrated into the control logic via the IO-Link, which is ideal for applications in which several thread variants need to be tested. Thanks to its high switching frequency, the sensor reacts reliably even during fast test cycles and enables continuous inline inspection.
With very small threads – from size M5 or smaller, for example – optical thread detection with reflex sensors reaches its physical limits. The laser spot then covers too large an area, which means that individual threads can no longer be clearly detected. In such cases, the use of a Laser Distance Sensors Triangulation from the wenglor P3 series is recommended, which provides measured values in micrometer resolution and also precisely detects minimal height differences.
However, for all applications in the M6 and larger range, the P1MH202 offers an optimum combination of precision, simplicity and economy.
The P1MH202 laser reflex sensor can be used to precisely detect and check threads up to size M6. Thanks to laser light, triangulation and background suppression, the sensor works regardless of color, surface or degree of gloss. Its compact format allows it to be used in tight mounting environments, while IO-Link offers easy integration into existing inspection systems.
With smaller threads, the optical solution can reach its limits – in this case, wenglor offers an alternative for high-precision measuring tasks with the P3 series. This means that thread detection remains flexible, reliable and tailored to the respective application.
