Trauzl lead block test

Test for the measure of explosive materials

The Trauzl lead block test, also called the Trauzl test, or just Trauzl, is a test used to measure the strength of explosive materials. It was developed by Isidor Trauzl in 1885.

Trauzl lead block before and after a test (1 – sand | 2 – Explosive and detonator | 3 – lead)

The test is performed by loading a 10-gram foil-wrapped sample of the explosive into a hole drilled into a lead 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).^[1] The hole is then topped up with sand, and the sample is detonated electrically. After detonation, the volume increase of the cavity is measured. The result, given in cm³, 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.^[2]

A variant of the test uses an aluminium block to avoid exposure of participants to lead-related hazards.

Examples

Explosive power of chemical explosives by Trauzl number:

Notes

1. Krehl, Peter O. K. (2008-09-24). History of Shock Waves, Explosions and Impact: A Chronological and Biographical Reference. Springer Science & Business Media. ISBN 978-3-540-30421-0.
2. Lepper, Bessie; F. Everett Reed; William E. Gordon (September 1955). "Lead-Block Test for Explosives". Industrial and Engineering Chemistry. 47 (9): 1794–1800. doi:10.1021/ie50549a028.
3. J. Köhler, R. Meyer, A. Homburg: Explosivstoffe. 10., vollständig überarbeitete Auflage. Wiley-VCH, 2008, ISBN 978-3-527-32009-7.