Kestrel 4000 Portal Weather Station
CORPS also carries a portable weather station that can measure wind, air pressure, and humidity.
The theory is that if an entity can effect air temperature that it most likely will effect pressure and humidity. If an entity reduces the temperature it will bring the air closer to its dew point therefore decreasing localized humidity and increasing the potential for appearance of small areas of mist near a significant cold spot. The air in the cold spot would be dryer as cold air holds less moisture. Energy is made of atoms which have mass. If the sign of an entity is a spike in electromagnetic energy, there should be an slight increase in pressure as mass is added to the localized atmosphere. The opposite could also be true. If an entity absorbs energy to manifest, there should be a slight decrease in pressure due to a decrease in mass in the localized atmosphere.
This tool is an important piece of equipment for CORPS as we like to measure as much data as we can get in order to support or refute reports of paranormal activity.
If you'd like more information on this piece of equipment, please visit this site.