Test Details
Test Purpose
The purpose of the Time/Pressure test is to determine whether igniting a substance under confinement will result in a deflagration with explosive violence. Applicable to homogeneous substances.
Test Variations
The Time/Pressure test is used in both Test 1 (c) and Test 2 (c). In UN Test 1 (c) the pressure is monitored to see if it reaches 2070 kPa (300 psig) whereas in UN Test 2 (c) the pressure is monitored to see if it transitions from 690-2070 kPa (100-300 psig) in less than 30 msec.
Key Parameters
| Key Parameter | Objectives | Origin | Specs |
|---|---|---|---|
| Confining medium (steel vessel) | Confined vessel protected with a burst disk | Cylindrical steel pressure vessel 89mm in length and 60mm external diameter | |
| Sample size | Provide sufficient mass to enable repeatable determination of the test outcome | 5 grams | |
| Number of trials | Obtain an accurate characterization of the test sample | 3 trials | |
| Ignition stimulus (igniter size and type) | Ensure a sufficient amount of the material is ignited | Electric fusehead with a 13mm square piece of primed cambric (linen fabric coated on both sides with a potassium nitrate/ silicon/ sulphurless gunpowder pyrotechnic composition) or equivalent | |
| Pressure transducer and recording system | Measure the pressurization rate within the steel vessel | Capable of responding to rates of pressure rise 690 – 2070 kPa (100 – 300 psig) in not than more 5 msec and not affected by hot gases or decomposition products |
Indicators
| Indicators | Detection Method | Assessment |
|---|---|---|
| Vessel pressure | Pressure transducer | Pressure rise of 690-2070 kPa (100-300 psig) in <30 msec: [Class 1] |
Setup Example
Rapid Deflagration (+) Example Photo
