To understand the pressure theory, you must first understand what barometric pressure is. Barometric pressure is the force applied by the atmosphere at any time, also known as “weight of the air”. It is important to know what the pressure is before investigating to gain a base reading. Depending on where you live the levels of barometric pressure is different. If you live in the coast, the barometric pressure is high. If you live inland than then barometric pressure is lower. The theory is that when a spirit manifests it may cause a sudden increase or decrease in pressure in a localized area. When this occurs you may feel a pressure change in your sinus cavity or in your ears. The feeling will be similar to the pressure change when flying in an airplane or going through a tunnel.
The equipment that we use to detect Barometric Pressure is listed below: