Hygrometer
Early Warning Signal of Paranormal Activity



Ghost Hunting Equipment: Hygrometer
Early Warning Signal of Paranormal Activity

A hygrometer is a device which is used to detect the changes in air humidity. Some ghost hunters believe this device can help detect paranormal activity and might be an early warning sign that paranormal activity will start to occur. In this video the individual is using a Nixie thermometer & hygrometer. Using IN-14 & IN-19 nixie tubes.


Hygrometers are instruments used for measuring relative humidity.

A simple form of a hygrometer is specifically known as a psychrometer and consists of two thermometers, one of which includes a dry bulb and one of which includes a bulb that is kept wet to measure wet-bulb temperature.

Modern electronic devices use temperature of condensation, changes in electrical resistance, and changes in electrical capacitance to measure humidity changes.


In a psychrometer, there are two thermometers, one with a dry bulb and one with a wet bulb.

Evaporation from the wet bulb lowers the temperature, so that the wet-bulb thermometer usually shows a lower temperature than that of the dry-bulb thermometer, which measures dry-bulb temperature.

When the air temperature is below freezing, however, the wet bulb is covered with a thin coating of ice and yet may be warmer than the dry bulb.

Relative humidity is computed from the ambient temperature as shown by the dry-bulb thermometer and the difference in temperatures as shown by the wet-bulb and dry-bulb thermometers.

Relative humidity can also be determined by locating the intersection of the wet- and dry-bulb temperatures on a psychrometric chart.

One device that uses the wet/dry bulb method is the sling psychrometer, where the thermometers are attached to a handle or length of rope and spun around in the air for a few minutes.


Dewpoint is the temperature at which a sample of moist air (or any other water vapor) at constant pressure reaches water vapor saturation.

At this saturation temperature, further cooling results in condensation of water. 

 
Some ghost hunters believe this device can help detect paranormal activity and might be an early warning sign that paranormal activity will start to occur.

 


Super Accurate Rectangular Digital Hygrometer


"Cooled mirror dewpoint hygrometers" are the most precise
instruments available. They use a chilled mirror and optoelectronic mechanism to detect condensation on the mirror surface.

The temperature of the mirror is controlled by electronic feedback to maintain a dynamic equilibrium between evaporation and condensation on the mirror, thus closely measuring the dewpoint temperature.

Modern instruments use electronic means of recording the information. The two most common electronic sensors are capacitive or resistive.

The capacitive sensors sense water by applying an AC signal between two plates and measuring the change in capacitance caused by the amount of water present.

The resistive sensors use a polymer membrane which changes conductivity according to absorbed water. Recently, an unbalanced AC Bridge approach was adapted for low power/energy operation and has shown to provide better measurement performance over a wide operating range.

To further increase accuracy in this same device, which combines a sensor in data logging instrument, a calibration method utilizing a large memory array was developed to maximize performance. In most instruments, resistive sensors can be read by common meters or data acquisition boards. Temperature must also be measured, as it affects the calibration of all these sensors.





Ghost Hunting Equipment