Cross-Physics Sensor Replacement in Industrial Control Circuits
Cross-physics sensor retrofits require matching phase delay, thermal drift coefficients, and input filter bounds before changing the transduction element.
ISO 13849-1 Safety Distance
Protection Zone Geometry
Calculated gaps between a hazard and a safeguarding device prevent personnel from reaching a dangerous area before the machinery stops. The iso 13849-1 safety distance ensures that light curtains or scanners are positioned far enough away to account for the total reaction time of the system. This calculation is a fundamental part of the machine risk assessment process.
Stop Time
Measurement begins the moment the sensor detects an intrusion and ends when the hazardous motion has completely ceased. This duration includes the internal delay of the sensor and the response of the safety relay and the braking time of the motor. Any increase in the mass of the machinery will extend this stopping time.
Sensor Position
Placement must also consider the speed of a human hand or body approaching the danger. Standardized approach speeds are used in the formula to provide a conservative estimate of the required gap. If the sensor is moved closer to the machine, the stopping time must be reduced to maintain safety.
Risk Category
Level of reliability required for the safety function depends on the severity of the potential injury. Higher performance levels require redundant sensors and monitored control circuits to ensure the system fails in a safe state. Periodic testing verifies that the stopping time has not increased due to mechanical wear or brake degradation.