The use of a laser grid does have scientific reason for doing so, on it's own it's a great tool for evidence gathering. If you add that to a device like a Mel Meter, even a K2 EMF meter, then it becomes a powerful tool.
With most investigations you start off slow, the use of a digital temperature gauge and maybe the Echo Vox at the start, you sense something, you then bring in the EVP recorder and the big guns; The laser grid and Mel meter and your recording throughout. This is real investigation and with this level of equipment set up, your chances of gathering real hard evidence has quadrupled.
I have placed six movies below which guides you through the use of the laser grid as well as the useful device the Mel Meter with Shadow Detection.