I have always been fascinated by the weather and was highly jealous of my best friend when he received a degree in Meteorology from Texas A&M University. My interest in the weather was a small part of my mental tool bag that I used for investigations as I am constantly aware of weather conditions as well as how it can factor in logical explanations of various events.
We all know that a standard tool for investigations is a temperature gauge. Many groups use a contact thermometer, which is not a good idea since it only measures the surface temperature. Though most groups know you get what you pay for and have gone out and purchased non-contact thermometers (which have come down significantly in price) which still have limitations, but are also a necessary tool for finding logical explanations to some potential paranormal problems.
One tool that gets very little recognition, but it discussed by many out there, is the use of a hydrometer. A hydrometer basically measures the humidity of a location based upon temperature and is stated as the relative humidly. Relative humidity is the percentage of water vapor required to saturate the air at the current temperature. The thing to know about relative humidity is that when the temperature increases so does the capacity for the air to hold more moisture. In other words, the relative humidity would appear to drop if the temperature increases (the air can now hold more moisture) and would appear to increase if the temperature decreases (it can hold less water).
What does this mean for ghost investigation?
Bringing various tools to measure the environment is scientific, as long as you know what the results mean and what the cause was to create the effect without jumping to conclusions. In other words, if you have this tool in your bag and have no idea why it does what it does there is no science behind it.
A hydrometer should be used in conjunction with temperature gauges to verify reasons why it would flux. Without this backup the readings mean nothing to paranormal research. Relative humidity may play a part in the appearance of paranormal events and attaching results with a hydrometer is a baby step in this direction. Documentation and experimentation is critical as is creating baseline readings throughout the investigation. Controlling the area of research is also critical. You should be aware of open doors, windows, drafts, sun coming through a window or heating one side of a house or parts of a structure. All of these things can have an effect on the information being gathered.
There is no reason to limit the areas of research as long as there is a benefit from using the tool or methods to a specific aspect of what you are researching. Do the ends justify the means? If you have a situation where the homeowner is scared out of their mind it might not be a good time to experiment with a hydrometer!
I would like to thank Tammy from OKC Paranormal in Oklahoma for looking for information about this subject from others through their Myspace page as well as sharing knowledge and information about this subject. This is how we will all learn and how this field will grow not in numbers, but in direction and valid research and information.