The Trauzl lead block test, also called the Trauzl test, or just Trauzl, is a test used to measure the
strength
Strength may refer to:
Personal trait
*Physical strength, as in people or animals
*Character strengths like those listed in the Values in Action Inventory
*The exercise of willpower
Physics
* Mechanical strength, the ability to withstand ...
of
explosive material
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An exp ...
s. It was developed by
Isidor Trauzl
Isidore ( ; also spelled Isador, Isadore and Isidor) is a masculine given name. The name is derived from the Greek name ''Isídōros'' (Ἰσίδωρος, latinized ''Isidorus'') and can literally be translated to 'gift of Isis'. The name has survi ...
in 1885.

The test is performed by loading a 10-gram foil-wrapped sample of the explosive into a hole drilled into a
lead
Lead () is a chemical element; it has Chemical symbol, symbol Pb (from Latin ) and atomic number 82. It is a Heavy metal (elements), heavy metal that is density, denser than most common materials. Lead is Mohs scale, soft and Ductility, malleabl ...
block with specific dimensions and properties (a soft lead cylinder, 200 mm diameter and 200 mm high, with the hole 125 mm deep, and 25 mm diameter).
The hole is then topped up with sand, and the sample is
detonated
Detonation () is a type of combustion involving a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations propagate supersonically through shock waves with ...
electrically. After detonation, the volume increase of the cavity is measured. The result, given in cm
3, is called the Trauzl number of the explosive.
The Trauzl test is not useful for some modern higher-powered explosives as their power often cracks or otherwise ruptures the lead block, leaving no hole to measure.
A variant of the test uses an
aluminium
Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...
block to avoid exposure of participants to
lead-related hazards
A hazard is a potential source of harm. Substances, events, or circumstances can constitute hazards when their nature would potentially allow them to cause damage to health, life, property, or any other interest of value. The probability of that ...
.
Examples

Explosive power of chemical explosives by Trauzl number:
Notes
Explosives engineering
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