The Ultimate Guide to Hygrometers

Hygrometers are a type of device that measure the humidity, or amount of water vapour, in the air. These devices are used to measure the amount of moisture in the air, which can be used to predict weather, control the moisture content of products and even help keep buildings and people healthy.

There are many different types of hygrometers, which can be used for different purposes. The most basic hygrometers are called psychrometers, and they measure the dew point of the air. A psychrometer is simply a wet and dry bulb thermometer with a hair dryer or other source of heated air attached to the wet bulb.

Other types of hygrometers use a combination of sensors and algorithms to measure the humidity. These devices are a lot more accurate than psychrometers, but they are also a lot more expensive.

The humidity or wetness of the air can be measured in a number of different ways. A hygrometer uses one or more of these methods to measure the amount of water vapour in the air.

The psychrometric method of measuring humidity is the most basic way to measure the amount of water in the air. This method consists of a thermometer and a hygrometer, which is basically a thermometer with a wet cloth covering the bulb. The temperature at which the wet and dry bulbs reach equilibrium is the dew point, and with this information you can calculate the relative humidity.

Why should you use a digital hygrometer?

Accurate results

Digital hygrometers are a lot more accurate than their analogue counterparts. They are also easier to read and don’t require calibration.

Easy to use

These devices are very easy to use, and don’t require any special knowledge to use them.

Long lifespan

Digital hygrometers are built to last, and can last for years without breaking.

Easily readable

Digital hygrometers are built with large displays that are very easy to read.

Low cost

These devices are not very expensive, and are usually cheaper than analogue hygrometers.

Who might need to use a hygrometer?

Hygrometers are used by a variety of people and industries. These devices are used in a number of different applications, including:

Product manufacturers

These devices are used to ensure that products are packaged and stored at the right humidity levels.

Manufacturers can use digital hygrometers to test the humidity levels of their products.


Builders use digital hygrometers to ensure that the humidity levels in the building they are constructing are within the right levels.


Homeowners can use a digital hygrometer to measure the humidity levels in their homes.

Healthcare professionals

Digital hygrometers are used by medical professionals to monitor the humidity levels in hospitals and nursing homes.


These devices are used by meteorologists to help them predict the weather.

What should you consider when buying a hygrometer?

It’s important to know what you want from your hygrometer before you go out and purchase one. There are a number of factors to consider when buying a digital hygrometer:


Digital hygrometers are relatively inexpensive, and usually cost around £20.


Some digital hygrometers are more accurate than others. It’s important to know how accurate the device you are looking at is.


Some digital hygrometers have large, easy to read displays, while others have smaller displays with less information.

Brand name

If you don’t have a preference for a brand, then it’s best to choose a brand that’s easily available.


You’ll want to choose a digital hygrometer that is reliable and built to last.


A warranty is always a good sign, and shows that the manufacturer of the device you are looking at has confidence in their product.

How to use a hygrometer

Before you use your hygrometer, you’ll often need to calibrate it. To calibrate the hygrometer, you’ll need to place the sensor in a jar with a known humidity level (often, because it’s filled with boiling water). However, it’s best to use a calibration kit that comes with your hygrometer.

Once your hygrometer is calibrated, you can use it to measure the humidity levels in your home. To measure the humidity levels in your home, place the hygrometer in a spot that receives a lot of air flow.

It’s best to place the hygrometer in a spot that’s away from heating vents, as this can cause the humidity levels to fluctuate.

Once you’ve placed your hygrometer in the right spot, you can check the humidity levels a few times a day to see how the levels change.

How to measure humidity without a hygrometer

There are a number of ways to measure humidity without using a hygrometer. These methods aren’t as accurate as using a hygrometer, but they are handy to have around if you don’t have a hygrometer.

One of the easiest ways to measure the humidity in your home is by using a common household item: a can of soda. To measure the humidity in your home, fill a can of soda with water and place it in a place that receives a lot of air flow.

Now, you can use the weight of the can to determine the humidity in your home. The more water that evaporates from the soda, the higher the humidity level.

Another way to measure humidity is by using a bowl of water. To measure the humidity in your home, fill a bowl with water and place it on a scale.

As the water evaporates, the weight of the bowl will change. This will tell you the humidity levels in your home, and you can use this information to adjust the settings on your humidifier or dehumidifier.

About the Author Marvin J. Snyder

I'm the research analyzer and data interpretation here at Weather Station Lab. I test various weather stations and share my conclusion here. Since my childhood, I had a passion towards weather and I'm always fascinated by that. Eventually, I pursued Ph.D. in Atmospheric Science from the University of Arizona. I hope my contribution will help you to know more about weather stations. Read more about us, here