Extremely high repeatability

Sensors that operate according to the triangulation method, such as the PT44 product series, impress with extremely high precision, because triangulation is one of the most accurate methods for optical distance determination.


The light emitted by the transmitter and reflected by an object hits the receiver. The receiver essentially consists of a converging lens and the actual sensor element. The converging lens focuses the incident light waves and transmits them to the photoelectric sensor element. The position of the light beam impinging here depends on the distance of the device to the object and thus on the angle of reflection. Thus, the object distance can be precisely determined and converted into a distance-proportional voltage (0 ... 5V) or current signal (4 ... 20mA). The switching point of the switching output is also freely programmable within the measuring range.


With this process and a very fine class 1 laser light, the sensors of the PT44 series achieve first-class repeatability. Expressed in figures, this is 10μm for the PT440300 (measuring range 25 ... 35mm) and 800μm for the PT440304 (measuring range 200 ... 600mm). Relatively speaking, these are 0.1% and 0.4% over the entire measuring range.


For physical reasons, the accuracy is always somewhat better in the range close to the sensor, because the angle difference for a certain distance change is significantly greater at the start of the measuring range than at the end of the measuring range.


In order to nevertheless be able to detect small objects from greater distances with the best possible precision, ipf electronic has expanded the sensor series with the PT440306. With an alternative measuring method, the time-of-flight measurement, a relative repeatability of 0.33% is achieved over the entire working distance of 250 to 3000mm. As with the other devices, parameterization is carried out via three integrated keys, the menu items and the measurement results can be read on the 4-digit 7-segment display.