Test Description
Test Purpose
The BATF and DoD use cap sensitiveness to distinguish between a high and low explosive. If the material fails the #8 cap test, then the BATF requires use of the high explosion table for storage siting and the DoD identifies the material as a 1.1 material in its unpackaged form. In manufacturing operations this type of material should be considered to have a mass explosion hazard. The #8 cap test, as used by the DOT or DoD is a good test for this purpose.
Equivalence
This test is equivalent to UN Test 5 (a) in the UN Manual of Tests and Criteria.
Test Variations
A witness plate or a cylinder of lead can be used to determine the test outcome
Key Parameters
| Key Parameter | Objectives | Origin | Specs |
|---|---|---|---|
| Confining medium | Provide minimal confinement of the substance | Cardboard tube | |
| Tube diameter (80mm min) | Sufficient diameter to be above the critical diameter of substances readily detonated by a standard detonator | 80mm diameter minimum, 160mm length | |
| Ignition stimulus (standard detonator) | Provide a standard intense mechanical stimulus | Standard No. 8 detonator | |
| Detonator placement | Ensure damage to witness plate is not a result of the detonator | Inserted centrally in the top to a depth equal to its length | |
| Witness plate or lead cylinder specifications | Evidence of reaction type | 1.0mm thick, 160 x 160mm steel plate or 51mm diameter, 102mm long lead cylinder | |
| Steel ring | Provide an air gap beneath the witness plate, allowing for deformation of the witness plate | 50mm height, 100mm ID, 3.5mm wall | |
| Substance density | Determine whether the substance in its in-process form is sensitive to the test stimulus | Substance to be tested as near as possible to the in-process density |
Indicators
| Indicators | Detection Method | Assessment |
|---|---|---|
| Damage to the witness plate or compression of the lead cylinder | Visual post-test inspection | Tear or penetration of the witness plate. Compression of the lead cylinder of 3.2 mm or more. |
No Damage to Witness Plate (-) Example Photo
Damage to Witness Plate (+) Example Photo
