Leakage

A well-sealed landmine may remain undetected by a dog under perfect conditions simply because no or little scent has been transported to the surface. To determine the availability of vapour at the soil surface, it is necessary to take flux rate (leakage) from landmines into account. It is known that some mines are easier to detect than others, but very little research has been undertaken to determine the flux rate from different landmines. A landmine leakage library could become as valuable to an MDD organisation in the future as technical data about metal content in landmines is for a manual mine clearance organisation today.

The GICHD works with Sandia and several demining organisations to determine flux rate from 30 different mine types. Acquisition of sufficient landmine types for flux testing is a challenge for analysis at Sandia National Laboratories. The best landmines for testing are those recently recovered from the field. These landmines have been aged in the local soils and landmine flux tests will more closely mimic actual field situations.

The TMM-1 (former Yugoslavia) appears to have a low explosive flux rate. A combination of metal casing and good sealing prevent explosive leakage. It may then be necessary to train the dog to detect traces of the paint coating		The PMN-2 (Russia) has a large rubber pressure plate with a high explosive permeability. This makes the mine an easy explosive detection target.

A choice between in-field chemical analysis and transportation of test soils back to Sandia National Laboratories was evaluated. It appears that returning flux chamber soils to Sandia National Laboratories is the best choice. Landmine flux testing involves establishing the mine in a test box at the field site, and then removing the mine 8-12 weeks later. The soil is sent to Sandia National Laboratories for analysis. A total of 90 landmine flux tests are planned: 10 types of mine will be used at each of 3 field locations, with 3 replicates of each mine type being used.

Countries where field labs are being established for measurement of flux rate include Angola, Mozambique and Cambodia. Mine types from these countries represent broadly the most common mine types found worldwide.