May it be a little more accurate?

In the last issue of INFO (No. 66), we presented the latest sensors in the OTQ8 series. Small diffuse reflection sensors with great performance. However, if there are applications for which the small light spot or narrow line is still too large, the PTQ80470 or the PTQ80475 could be the right devices.

Both sensors work on the principle of background suppression by triangulation. The setting of the sensing distance is carried out via the familiar, simple teach procedure in which the rear panel is touched with a ferromagnetic tool. A laser diode of laser protection class 1 with visible red light is installed as the light source in each case.

The PTQ80470 has a point-shaped light beam. At the focal point, at a distance of 40 mm, the diameter of the light spot is only 0.25 mm; at the maximum adjustable sensing range of 120 mm, it is 4 mm. This means that not only can very small objects be detected, but they can also be detected quickly thanks to the short response time of 0.5ms.

The PTQ80475 has a fine laser line. The focal point is at a sensing range of 60mm, whereby the line is 28mm long and 0.5mm wide. At the maximum adjustable sensing range of 120mm, the length is 60mm and the width is 2mm. With this sensor, an object can be recognized regardless of its position as long as it is within the detection range of the line and reflects enough light at the appropriate bracket. Especially when detecting round objects such as wire or objects with an uneven surface, the PTQ80475 shows its advantages. The response time is slightly longer at 2 ms, as the processor has to perform more iterations to precisely activate the switching output due to the line's larger optical measuring range.

The electrical connection is made via a 4-pin M8 cable connector; one PNP switching output works on PIN 4 (black core) as normally open and on PIN 2 (white core) as normally closed (nc).

The sensors also have a special feature with regard to mechanical installation, as the sturdy metal inserts in the mounting holes are equipped with an M3 thread. Together with the optionally available brackets (e.g. AO000580) or the universal mounting AY000116 the installation is significantly simplified.