Also known astatva sadhnatatva identificationprithvi jal agni vayu akash
Before entering a land, note which nostril is active and how far down and in what direction the breath flows; step onto the land first with the foot of the active side, walk one full round while watching the breath, and read the land's quality and defects from it.
On the land, starting from the point of entry
Besides measuring how many angul the breath reaches, the active element (tatva) can be recognised from the state of the mind: steadiness, joy, restlessness, anger or indifference.
Each sense works through one element: sight through fire, hearing through space, touch through air, smell through earth and taste through water; a weak sense points to an imbalance of its element.
The earth element (prithvi tatva) has the longest share, 20 of every 60 minutes among the five tatvas of a swar. In the same way, the earth element of the land, its land energy, carries 70 percent of the result in vastu.
It is best to remove shoes and slippers, though wearing them causes no real problem, because the reading comes from the air you inhale after it meets the land, and you can breathe either way. Barefoot, the current also enters the body directly through the bhoomi chakra of the earth element in the big toe of the right foot, in addition to the nose.
Use the pit water method taught in the previous class. With swar, walk the whole land: if the same swar keeps running with the water or earth element throughout, whether it is Chandra swar or Surya swar, the land is good.
It needs proper tatva swar training; the element is known from how many angul the breath reaches. It also shows in the mind: steadiness means the earth element, joy the water element, restlessness the air element, anger the fire element and indifference the space element.