Typical applications for HDDM+ technology include distance measurement for quality control in electronics production, LiDAR multi-dimensional object detection and position determination in mechanical and plant engineering, and determining the position of industrial cranes or vehicles. The sensing range of HDDM+ sensors is up to 1.5 km on retro- reflective tape. For example, model DT1000-S11101 has a range up to 460 m with a typical measurement accuracy of ±15 mm for natural objects and an adjustable resolution from 0.001 to 100 mm. Inductive Inductive proximity sensors like the IME series from SICK can detect ferrous and non-ferrous metal objects. These sensors consist of an inductor-capacitor (LC) resonant circuit that generates a high-frequency alternating electromagnetic field. The field is dampened when a metallic object enters the detection range. The dampening is detected by the signal evaluation circuit and an amplifier that produces the output signal (Figure 4). Two important specifications for the sensing distance of several proximity sensor technologies are the nominal sensing distance (Sn) and the secured sensing
Figure 5: In a capacitive proximity sensor, an oscillating circuit produces an electrostatic field that changes characteristics when the target to be sensed enters the field. (Image source: SICK)
distance (Sa). Sn does not consider manufacturing tolerances or external influences like operating temperature. Sa takes into consideration both manufacturing tolerances and variations in operating conditions. Sa is typically about 81% of the value of Sn. For example, for the model IME08- 02BPSZT0S inductive sensor, Sn is 2 mm and Sa is 1.62 mm.
When an object enters the electrostatic field, the amplitude of the oscillations in the resonant circuit change based on the dielectric properties of the material. The signal evaluator detects the change, and an amplifier produces the output signal (Figure 5). Like inductive proximity sensors, there are several specifications related to the sensing distance of capacitive proximity sensors including Sn, Sa, and a reduction factor. For example, the model CM12-08EBP-KC1 has an Sn of 8 mm and a nominal Sa of 5.76 mm. The object to be sensed must be at least as large as the sensor face and the sensing distance varies with the reduction factor of the material. Reduction factors are related to the dielectric constant
Capacitive sensing
Like inductive sensors, capacitive proximity sensors use an oscillator. In this case, an open capacitor is used where the active electrode in the sensor produces an electrostatic field relative to ground. These sensors can detect the presence of a wide range of materials including metallic and non-metallic objects.
we get technical
23
Powered by FlippingBook