Selecting the correct light curtain for an industrial automation line requires matching optical performance specs, response speeds, and hardware interfaces to the specific hazards of the machinery. Because optoelectronic guarding directly impacts worker safety and regulatory compliance, industrial safety engineers must evaluate four key design parameters when choosing a light curtain system.Detection Resolution and Beam Spacing: Match the optical axis pitch to the required level of protection. Use 10 mm beam spacing for close-in finger protection near pinch points, 20 mm spacing for general hand detection on assembly stations, and 40 mm or larger beam spacing for limb and body detection at perimeter access points.Protective Height and Beam Count: Select a curtain height that covers the entire hazardous opening. Modular models offer beam counts ranging from 4 up to 52 beams, accommodating protective heights from 100 mm to over 2000 mm to ensure full coverage without dead zones.Response Time and Safe Distance Calculation: Ensure the system response time ($\le 10\text{ ms}$ to $20\text{ ms}$) is fast enough to stop dangerous machine motion before a worker can reach the hazard. This response speed dictates the minimum safe mounting distance between the light curtain and the dangerous machine parts.Output Interface and Enclosure Rating: Verify output logic compatibility—such as dual NPN or PNP solid-state outputs for direct PLC integration, or safety relay dry contacts. For harsh environments exposed to coolant, cutting fluids, or outdoor elements, select IP65 to IP68 waterproof aluminum housings with anti-interference optics to ensure stable long-term operation.