LBC Series Laser Blade Counters - Sensor Instruments - #1

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LBC Series • Laser Blade Counters Product Information info@sensorinstruments.de • www.sensorinstruments.de (2006-04-20) LBC Series / Page 1 of 5 Sensor Instruments GmbH • D-94169 Thurmansbang • Schlinding 11 Tel. +49 (0)8544 9719-0 • Fax +49 (0)8544 9719-13 LBC Series Laser Blade Counters The LBC Series laser blade counters are primarily used for detecting and counting the vanes or blades of turbochargers and fans. The high scanning frequency and the standardized data evaluation of the laser sensor allow its application with objects of different color and speeds of up to 30000 rpm. The visible laser spot and the automatic power correction feature facilitate sensor alignment to the respective objects. An analog signal (0 ... +10V) and a digital signal (0V/+24V) are available as outputs. Characteristics Parameterisation under Windows® with software LBC-Scope V1.0 The sensors can easily be set with the help of a Windows® user interface in which the sensor signals are displayed in numerical and graphical form; the user interface also provides various software algorithms and setting parameters. Parameters such as e.g. - Threshold (sensitivity) - Hysteresis - Laser power mode (static or dynamic) - Output pulse lengthening - Dead time (static or dynamic) can be set with the software. Functional principle of the sensor The laser sensors of LBC Series operate according to the shadowing principle, i.e. a laser spot that is projected onto the vanes is viewed from two different angles. The viewing angle of receiver A is almost identical to the emitted laser beam, the viewing angle of receiver B, however, is angular with respect to the laser beam. Receiver A is used to keep the laser power constant. Viewed from receiver B, the laser spot ist now completely covered in a certain rotation angle range, which guarantees a highly reliable detection of the impeller vanes. In order to avoid double or multiple counting, a special algorithm is applied that locks the laser sensor for a certain time (the so-called dead time) after a vane is detected. Furthermore, standardized (intensityindependent) evaluation and automatic laser power correction almost completely suppress surface influences. The special geometry of the sensor allows it to work in a distance range of 150 mm to 300 mm from the impeller. Speeds of up to 30000 rpm. are displayed both in a digital (0V/+24V) and analog (0V .. +10V) way. SIGNAL A SIGNAL A SIGNAL B SIGNAL B SIGNAL B NORM = SIGNAL A + SIGNAL B NORM * 255