What Is A Hygrometer?
A hygrometer is a sensitive measuring instrument. It measures one thing and one thing only. It is used to measure the relative humidity – the amount of moisture – in the air.
Hygrometers come in different styles and designs. There are digital and analog hygrometer options. Also, many hygrometers come with temperature and barometer gauges built-in, making them mini weather stations.
Why Do You Need A Hygrometer?
Hygrometers allow you to accurately monitor the moisture content in the air you breathe. In a home, when humidity is high, condensation can appear on walls, ceilings, windows and furniture, which can lead to the formation of mold and mildew.
With high humidity levels indoors there can be different kinds of damage. The mold and mildew can affect allergies and promote corrosion or warping in wood construction and furniture.
For more information on how to get rid of condensation, have a look at this article.
The opposite end of the scale is also damaging. With low humidity, the air is dry and can affect breathing conditions in many people. There are other concerns as well.
Drier air can result in skin irritations, rashes, cracked skin, and itchiness. Dry air can also cause problems with furniture with cracking and breaking.
For information on the best humidifiers that you can use to alleviate low humidity conditions, see this article.
A digital or analog humidity meter will assist you in keeping a safe level of humidity in your immediate surroundings. A hygrometer is used with a dehumidifier or humidifier to control relative humidity.
How Does A Hygrometer Work?
There are several basic measuring styles of hygrometers. They are surprisingly simple in concept. We will outline some of the more common styles below:
1. Wet Bulb/ Dry Bulb
This type of hygrometer contains two different thermometers. One has a wet bulb and the other has a dry bulb.
As water evaporates from the wet bulb thermometer the temperature decreases (this is similar to when your skin is wet and you blow air onto it – it feels cooler). When the difference in temperature between the wet and dry bulb thermometers is compared, the relative humidity can be determined.
2. Human Hair
A human hair will expand or contract depending on the humidity of the air. A needle gauge is used in this style of the hygrometer.
The gauge measures how much the human hair has expanded or contracted. That data is used to calculate the relative humidity in a specific area.
Resistance and capacitance are used to measure humidity. The capacitive style of hygrometer uses two metal plates with air between them.
The moisture in the air affects the amount of static electrical charge which can be stored in the plates. This value can then be used to indicate the relative humidity.
4. Dew Point
The saturation of moist air in a gas is how this hygrometer works. These tend to be the most accurate of all hygrometers in the marketplace.
How Are Hygrometers Installed?
Portable hygrometers are easy to install. Designs come with many different mounting options. Some are tabletop designs. Others can buy hung with screws, hooks or Velcro fasteners.
What Are The Different Types of Hygrometers?
There are two basic types of hygrometers. They fall under the categories of analog or digital.
The way in which analog hygrometer works is based on a coil of thin metal which is bonded to a hygroscopic material that can absorb moisture.
As the strip collects moisture it expands causing the coil to bend or rotate. The coil is attached to a needle that moves accordingly and provides a reading on a dial face.
When the moisture on the absorbent material begins to evaporate, the coil contracts. This moves the attached needle to different reading points on the dial.
The majority of digital hygrometers use a resistive or capacitive sensor. Electricity flows through a small piece of moisture absorbent material that is exposed to the air.
When the amount of moisture absorbed changes, the electrical properties do as well. This is the data used to calculate the relative humidity.
Once the calculation is complete, a measurement is sent to the digital display which provides a numerical value. This is the humidity reading for the area.
For more information on digital hygrometers, make sure you check out this article.
Our Picks Of The Best Analog Humidity Meter Options
Here is a look at some of our favorite analog hygrometers:
Zoo Med Economy Analog Dual Thermometer and Humidity Gauge
Featuring easy to read analog temperature meter dials, this product allows you to monitor both the temperature and humidity with one unit. The dials contain color-coded zones to help you determine when heat and moisture levels are in need of correction.
This analog thermometer hygrometer unit is primarily designed for terrariums or other small enclosures but can be used for other applications as well.
The entire piece has a Velcro back to allow for easy mounting and removal for cleaning purposes or for placing in a different location.
- Inexpensive tool for measuring both temperature and air moisture content
- Works well
- Easy to read and color codes help identify safety zones
- Uncomplicated design with dials for each reading – temperature, and humidity
- Velcro backing not very effective in some applications
- Cheap looking design
- Readings not very accurate when compared to more precise instruments
Caliber 4R Gold Digital/Analog Hygrometer
This is an accurate digital/analog monitor with an advanced humidity sensor that is precise to 1% plus or minus. The unit can be recalibrated by the user and the design features a magnetic mount.
The dial is color-coded for easy reference and there is a battery included. Following manual analog hygrometer calibration, this unit is set to go.
- Attractive looking measuring device
- Once calibrated the accuracy is extremely good
- Color codes include a Green Zone for those who use humidors to store cigars
- Needs to be calibrated once the package arrives
- Readings are slower than other similar designs
- Display can only be read from viewing directly from the front
Bjerg Instruments Antique Brass 8” Indoor Outdoor Thermometer Hygrometer
The large 8-inch diameter of this indoor/outdoor thermometer and humidity gauge is perfect for many different applications. The 5.5-inch diameter dial face is easy to read and displays Celsius and Fahrenheit temperatures.
The analog humidity gauge is at the bottom of the unit. Featuring steel construction, this stylish instrument comes with an antique brass finish and has a glass lens.
- Very attractive, solid design
- High level of accuracy with the readings
- Works extremely well inside or outside of the home
- A bit heavier than many units so hanging it up requires some thought for placement
General Tools A600FC High-Temperature Analog Thermo-Hygrometer
Need to keep an eye on how your humidifier or dehumidifier is doing? Then this could be your choice. The attractive analog hygrometer thermometer design features a stainless steel case and flange mount make this an attractive looking unit… but there is more to it than meets the eye.
The temperature range that can be monitored goes from 30 to 250 degrees F (-1 to 121 degrees C) and the accuracy is noted at +/- 1.8° F (+/- 1° C).
The relative humidity range is from 10 to 95% and is accurate to +/- 6% of the reading. The temperature resolution is 2 degrees F (1 degree C) and RH resolution is 2% making this one of the best analog hygrometers for ease of use and accuracy.
- Well-made, sturdy, solid construction with a high-quality appearance
- Extremely accurate
- Cannot be used outdoors
- Reported as having mounting holes but did not come with screws included
La Crosse Technology 18” Atomic Outdoor Clock Temperature Humidity
This is truly a multi-purpose instrument. The time feature is radio-controlled and includes the analog hygrometer and thermometer readouts. It is also designed for use either indoors or outdoors.
You can even select from four different US time zones for accuracy. This time, temperature and analog humidity meter are powered by a single AA battery (not included).
- Will automatically adjust time according to the nearest atomic-powered time station
- Attractive design that fits in wherever it is placed
- Solid construction
- The analog hygrometer accuracy provides reliable readings
- Time will automatically set as soon as a battery is installed, this may be unnerving for some
- Default time is Pacific but can be changed to the correct time zone with optional buttons
Ambient Weather Thermometer, Liquid Barometer, Hygrometer Clock Weather Station
Designed as a traditional weather station, this work of art, as the manufacturer refers to it, can fit comfortably in a library, study, office or restaurant setting.
The weather station features a rich wood frame and measures more than just temperature. Other readings come from barometric pressure and humidity. It also contains an analog clock.
The storm glass barometer looks like a science project and it does provide much in the way of a conversation starter. This analog hygrometer thermometer is unique for that reason.
- Classic look with the wood and glass elements
- A real conversation starter depending on where you use it
- Features combination of temperature humidity and barometer gauges
- Not as accurate as expected
- Some users consider the product to be of poor quality
- You have to supply your own colored water in the glass barometer
Lily’s Home Analog Weather Station with Galileo Thermometer, Hygrometer, Barometer
This unit has an 11-inch Galileo thermometer on an oak base. There’s also a glass etched barometer and wood-framed hygrometer and blue colored powder all included.
There are a total of 5 different color-coded floats in the 11.4-inch tall Galileo thermometer. Each has a gold-plated tag noting temperatures between 64 and 80 degrees F.
The glass barometer has an etched globe with blue powder, a plastic syringe, and tube to allow you to insert colored water into the globe. The oak framed analog hygrometer measures 2.5-inches in diameter. All instructions are included.
- Attractive design made with quality products
- Functional readings from all instruments making this a useful tool
- Great design for an analog thermometer hygrometer
- Educational in teaching Galileo’s original thermometer concept
- Instructions are included but are a little vague in places
- Some users report damage resulting from shipping
The Benefits of A Hygrometer
There is no doubt that a device that measures humidity can come in handy in our daily lives. But what are the real benefits of such a tool?
Hygrometers allow us to adjust the conditions of our living space for more comfort. When this occurs we improve the conditions that affect our health.
You could say that the best analog hygrometers are great tools to have to ensure a comfortable environment for ourselves. But it is not just our personal health and wellbeing that is improved with proper humidity levels.
They are also handy tools for monitoring humidity levels for specific applications, such as in terrariums, humidors, and other locations where specific humidity levels are critical.
Humidity also has an impact on our pets and also can cause damage to homes and property if not properly controlled.