Hygrometer Analog Vs. Digital
- Most simple hygrometers use an analog spring system. This spring is designed to move according to changes in humidity, which in turn affect the material of the spring and how tensely it is wound. Changes in the spring are displayed in a gauge or dial format. Another simple hygrometer uses two different types of thermometers, dry and wet, and compares the temperature readings between them to determine local humidity levels.
- Another traditional type of hygrometer makes use of a sensitive, hair-based device. Some of the first hygrometers used human hairs, attached to sensitive springs that measured their diameter. As humidity increased, the hairs would swell, and the swelling would be recorded by the spring and shown on dials. Today, synthetic hairs are often used for similar systems.
- Digital hygrometers replaced springs and hairs with sensors that keep track of an electric current. The current is affected by humidity levels, so by monitoring changes, the sensors can produce very accurate humidity readings. Unlike analog hygrometers, digital versions have no moving parts and do not need to be recalibrated. Because the information is digital, a memory of past readings can also be stored. Information concerning trends, highs and lows can be transmitted wirelessly to other devices.
- There are very few digital hygrometers that stand alone, because humidity information is most useful when combined with other readings. Most hygrometers are combined with thermometers, clocks and GPS units that provide a variety of useful outdoor information.
- Hygrometers are used prominently in three different applications. Traditional versions (apart from ornamental use) are used by cigar aficionados to keep careful track of humidity conditions where their cigars are kept. More complicated digital versions are used by scientists and aircraft to monitor weather conditions, important for tracking storm fronts and picking up on early changes in environmental conditions. Hygrometers also are used for outdoor activities such as hiking and camping when knowing humidity levels can be useful.
