UL 1993 Figure 9.3 Articulated Test Probe

The UL 1993 Figure 9.3 Articulated Test Probe is an essential safety compliance instrument designed for accessibility testing of medical electrical equipment, including infusion pumps, patient monitoring systems, and diagnostic ultrasound devices. This precision tool replicates human finger articulation through its flexible joint mechanism, utilizing a 25.4mm diameter stainless steel test finger to access restricted openings such as equipment chassis seams, control panel apertures, and ventilation slots to identify accessible hazardous live components or thermal hazards.

The probe incorporates a 12.7mm radius spherical tip to prevent damage to sensitive medical device surfaces and features an insulated nylon handle for operator protection during testing procedures. The 31.75mm tail diameter provides mechanical limitation against excessive insertion depth. When applying the specified 10N ± 0.5N thrust force to simulate inadvertent human contact scenarios, this instrument ensures strict compliance with international medical equipment safety standards including UL 1993, IEC 60601-1, and GB 9706.1 requirements for hazardous part accessibility verification.

Technical Specifications

• Tool Classification: Articulated Test Probe (UL 1993 Figure 9.3 compliant; for hazardous part accessibility assessment in medical electrical equipment)
• Construction Materials: 304 stainless steel test finger with nylon insulation handle
• Critical Dimensions:
  • Test finger diameter: 25.4 mm (1.00 inch)
  • Test finger length: 101.6 mm (4.00 inches)
  • Spherical tip radius: 12.7 mm (0.50 inch)
  • Tail diameter: 31.75 mm (1.25 inches)
• Articulation Characteristics: Single-plane articulated joint design; maximum bending angle: 90° ± 10°; maintains mechanical integrity under 10N applied force
• Applied Test Force: 10N ± 0.5N (simulates accidental human contact per medical device safety standard requirements)
• Primary Function: Detection of accessible hazardous live parts and thermal components in medical equipment; simulation of human finger articulation; verification of compliance with international medical safety standards including UL, IEC, and GB/T requirements

Standardized Test Protocol

1. Conduct visual inspection of probe assembly: verify joint integrity, test finger straightness, insulation condition, and surface finish; confirm electrical conductivity using appropriate verification equipment.
2. Power the equipment under test (EUT) to normal operating conditions (e.g., patient monitor in standard monitoring mode).
3. Grasp insulated handle and utilize articulated joint to guide 25.4mm test finger into EUT access points (chassis interfaces, control openings, ventilation pathways).
4. Apply consistent 10N thrust force—terminate procedure if mechanical obstruction prevents further insertion or if hazardous condition is detected.