Triangle Probe for UL 1278 Figure 10.3

This UL 1278 Figure 10.3 Triangle Probe is a precision safety instrument designed for assessing portable electric tools, including angle grinders, circular saws, and jigsaws. Its distinct triangular stainless steel tip is engineered to access extremely narrow gaps, such as those between tool guards and blades or around switch housings, which standard round probes cannot penetrate. The probe is equipped with an insulating nylon handle to ensure tester safety by simulating accidental contact, thereby verifying the inaccessibility of hazardous moving parts, such as blade shafts and gears, or live components.

Specifications:
Probe Type: UL 1278 Figure 10.3 Triangle Probe (for narrow-gap testing in portable electric tools)
Tip Material: Stainless steel (rigid, corrosion-resistant)
Handle Material: Nylon (fully insulating, heat-resistant up to 100°C; non-slip grip for precise gap insertion)
Key Dimensions:
– Triangle Base Length: 69.9mm
– Triangle Height: 139.7mm
– Probe Thickness: 1.6mm

Test Procedures:
1. Inspect the probe for damage (bent tip, cracked handle) and confirm the integrity of the triangular shape.
2. Power on the electric tool and activate its moving components (e.g., saw blade, grinder wheel).
3. Hold the insulating handle and align the triangular tip with ultra-narrow gaps (e.g., guard-blade seams).
4. Apply a steady 10N thrust to the probe—stop if resistance from internal parts is felt.
5. Check if the tip contacts moving components (blades, gears) or live wires.
6. Record pass/fail results and power off the tool.

Applications:
1. Safety testing of angle grinder guard-blade gaps (per UL 1278:2023 Figure 10.3) to prevent gear access.
2. Verification of jigsaw blade guide gaps to avoid contact with moving linkage parts.
3. Quality control for belt sanders (narrow guard gaps around sanding belts) during manufacturing.
4. Post-production audits of reciprocating saws to comply with U.S. UL 1278 narrow-gap safety standards.