Laser digital light barriers
With their sturdy metal housing and their high type of protection the laser light barriers of series D-LAS are designed for demanding applications in machine construction.
The features of D-LAS light barriers at a glance:
Collimated laser beam
The laser light beam that is emitted by precision lenses (asphere made of glass) allows the detection of smallest objects (e.g. threads) even in case of large transmitter/receiver distances (depending on type and aperture distances up to 100m).
- Telecentrical design
- Exact shadow projection onto the receiver
- The distance of the measuring object from the transmitter or receiver over a wide range has no influence on the measuring signal
Homogeneous light distribution
The use of high-precision apertures in the transmitter ensures optimum adaptation to the respective application. Apart from a large variety of standard apertures special apertures can also be realized.
The aperture ensures a homogeneous light distribution in the beam and a sharp beam limitation.
Adjustable laser power
The laser power of transmitters of type D-LAS1, D-LAS2, and DLAS90 can be adjusted through the current control input (I-Control). With this input the laser also can be switched off, it can therefore be used for testing the laser light barrier (test input).
High positioning accuracy
In conventional light barriers the switching threshold is adjusted by means of a potentiometer. It depends on a fixed voltage (absolute value). As a consequence the switching point shifts with increasing dirt accumulation.
In the laser digital light barriers of the D-LAS series, however, dynamic correction of the switching threshold compensates the effect of dirt accumulation by way of continuous monitoring of the maximum value at the receiver. This means that increased dirt accumulation does not lead to a shift of the switching point.
In addition to the switching signal the laser light barriers of type D-LAS1 and D-LAS2 also provide an analog signal. This "monitoring" of the analog voltage allows improved evaluation of the switching signal. The output also is suitable for measuring purposes.
When an object passes through the laser light beam of a D-LAS1-D light barrier it triggers a voltage pulse whose pulse duration is independent of the time the object stays in the laser beam. The pulse duration is set to a fixed value of 10 ms.
If intensive external light sources must be expected in a laser light barrier application, it is recommendable for safety reasons to use a pulsed system (D-LAS1, D-LAS3, D-LAS90, D-LAS90-VACU). Due to the use of narrow-band electronic filters only the modulated light of the transmitter is detected. Even pulsed light sources such as flourescent lamps have no influence on the switching reliability.
In case of high switching frequency requirements a non-pulsed system can be used. Here external light suppression is ensured by means of narrow-band optical filtering. Therefore constant-light light barriers are suitable for fast processes or for measuring objects moving at high speed.
With the help of the analog output constant-light barriers of series D-LAS2, D-LAS-34, D-LAS-34/90, D-LAS-ED1 can also be used for measuring tasks.