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Safety light screens offer advanced features and flexible machine guarding over alternative safety methods
Within most manufacturing environments, production requires a working balance of machines and personnel. While this interaction is necessary, it can also be dangerous, with billions of dollars a year expended on machinerelated accidents in the workplace. According to an American Society of Safety Engineer's fact sheet, "Indirect costs of injuries may be as much as 20 times the direct costs, including costs from accident investigation, low employee morale, retraining workers, repairs, and production delays. Studies and case history indicate for every $1 invested in a safety and health program, $3-$6 are saved because injuries, illnesses, and fatalities decline, medical costs and workers' compensation costs decrease, and productivity increases."
Due to the wide range of hazards present in any industrial plant, facility managers need safety solutions that are cost-effective and flexible. Safety light screens provide a flexible safeguarding solution with versatile mounting options, numerous cascading capabilities, and broad applications suitability.
Safety light screens (or curtains) are optoelectronic devices that can detect the presence of opaque objects, such as a hand, arm, or foot, upon entering the sensing field. The emitter/ receiver pair is comprised of two basic components, an LED array, which emits infrared light beams, and a phototransistor array that detects the corresponding beams. The emitter modulates the light at a specified frequency and "code" that the phototransistors detect, allowing the internal logic to accept only that particular pulse of light and to ignore signals from external light sources. This precludes factory floor ambient light from affecting the performance of the safety light screen.
Guarding points of access to machine hazards, safety light screens will prevent or halt machine operation when an object is detected within the sensing field, protecting personnel from injury and equipment from damage. When all the phototransistors detect light from their corresponding LEDs, the light screen is "complete" and the safety outputs turn ON, which allow the machine to operate. However, once a hand or arm interrupts the beams of light, the light screen detects the presence, which triggers a stop signal to the safety-related controls of the machine. The machine immediately reacts, stopping the hazardous machine motion or removing the hazardous situation, until the...