UL Accessibility Knife Probe of UL 749 Figure 9.2 SB0504A

Specifications:
• Probe Type: UL 749 Figure 9.2 SB0504A Accessibility Knife Probe
• Knife Tip Material: Stainless steel (thin, rigid, corrosion-resistant; maintains sharp edge for gap access)
• Handle Material: Nylon (fully insulating, heat-resistant, non-slip for controlled force application)
• Key Dimensions:
– Knife Tip Width: 6 mm ± 0.1 mm
– Knife Tip Thickness: 1 mm ± 0.05 mm
– Effective Tip Length: 50 mm ± 0.2 mm
– Handle Length: 130 mm ± 0.5 mm
– Total Length: 180 mm ± 0.5 mm
• Applied Thrust: 50N ± 1N (simulates moderate force on narrow gaps in industrial enclosures)
• Core Function: Verifies accessibility of hazardous live/moving parts in narrow gaps of industrial control equipment per UL standards

Test Procedures:
• Inspect the probe (no bent knife tip, cracked handle, or loose connections) and confirm thrust calibration.
• Power on the industrial control equipment and let it reach normal operating mode.
• Hold the insulating handle and align the knife tip with narrow gaps (e.g., panel seams, button slots).
• Apply steady 50N thrust to the probe—maintain force for 5 seconds (per standard guidelines).
• Check if the tip touches hazardous components (e.g., exposed wiring, relay parts).
• Record whether the equipment meets safety requirements (pass/fail).

Applications:
• Safety testing of industrial control panels (e.g., factory automation controllers) per UL 749:2023 Fig 9.2.
• Compliance checks for motor control centers and switchgear to block narrow-gap access to live parts.
• Verification of non-patient-contact medical auxiliary equipment (e.g., lab sample processors) per UL 61010-1:2023.
• Quality control for industrial sensor enclosures (e.g., temperature/pressure sensors) during manufacturing.
• Post-production audits of automated assembly line control units to meet U.S. industrial safety standards.