All You Need to Know About Hygrometers

Hygrometers have multiple uses, but the main function of the device is to measure the amount of humidity in the air. The device uses calibration and calculation of temperature and pressure change to measure moisture content in the air. These tools are useful in homes, office buildings, and industrial and manufacturing processes where even small changes in humidity can affect production. One of the major applications of LED thermo hygrometer is to check the integrity of cold chains during the transport and warehousing of pharmaceutical products and frozen food. 

Furthermore, a simple hygrometer is suitable for non-professional purposes. There are many such important points that you should know before buying a hygrometer.

Here is all you need to know about this humidity measuring instrument called a hygrometer. 

Major Types of Hygrometers

When we talk about the main types of hygrometers, they are of two types. The first one is an analog hygrometer, while the other one is a digital hygrometer. However, when we discuss the types of hygrometers based on their functions, they are of the following types. 

Mechanical Hygrometer:

As the name suggests, these hygrometers are based on mechanical principles, built using organic materials. These materials are pieces of twisted fibers that react well with humidity as they contract and expand according to humidity. As they are tightly twisted, the twist tends to loosen up when there is high humidity. On the other hand, when it is less humid, the fiber tightens the twist. 

Electronic Hygrometer:

Experts use these hygrometers to measure electrical resistance or capacitance caused due to changes in relative humidity. Two metal plates are used to measure capacitance. 

The capacitive type device calculates the humidity through the ability of metal plates to store electrical charges. These electrical charges are directly proportional to the change in moisture. While in a resistive type device, the electricity passes through the ceramic substance present in the air. When there is high humidity, more water vapor causes the ceramic to contract, which induces modified resistance.

Dew Point Hygrometer:

Dew point hygrometers are useful for measuring the saturation of moisture in a gas. Most industrial spaces and greenhouses use these popular devices. Usually, they consist of a polished metal mirror cooled at constant pressure and constant vapor content till the moisture starts to condense on it. The process of condensation initiates when a metal temperature reaches its dew point. They have their uses in saunas, museums, incubators, humidors, and even for maintaining musical instruments like violins, harps, guitars, and pianos. 


Also known as wet and dry bulb thermometers, psychrometers use two thermometers. The difference in temperature is calculated when evaporation happens in the wet bulb, which causes its temperature to fall lower than the dry bulb. This equipment is useful for measuring outdoor humidity. They are also excellent for measuring humidity and moisture in areas with dry storage conditions. 

Gravimetric Hygrometers:

This device measures humidity by segregating the water from the gas and also determining the masses of the gas and water separately. It is one of the most accurate methods of measuring air moisture content. However, it is a complex and challenging device to use. That’s why users reserve them for calibrating less accurate hygrometers. 

What are the Factors to Consider When Buying a Hygrometer?

Before purchasing a hygrometer, there are some essential factors that you should keep in your mind. These factors will help you invest in the right device. So, read them carefully! 


Before choosing the right model, you need to consider the specifications like user interface, data logging, power source, and also access to historical data. The alerts and updates also enable users to monitor humidity remotely. Moreover, ensure that you can connect the device to different sensors as one system in case you need to monitor several places at once. Also, consider the +/- RH ratings for digital units. 


Hygrometers have their applications for home use, industrial settings, greenhouses, wine cellars, cigar warehouses, and manufacturing. Select your hygrometer based on its use or application type. For example, If you want a record of humidity changes, pick the one that records data at user-specified intervals. Or, if you need a device to measure the temperature and humidity for warehouses, choose an LED Thermo hygrometer. 


The size of the equipment also matters as it affects the buying decision. Various sizes are available for different purposes. For example, you need bigger keys to accommodate users wearing protective gloves in the food processing industry. So, choose the size of the device on the basis of its purpose. 

Material Type:

Before investing in a hygrometer, make sure the material used to make the device is good and durable. For example, consider buying a device made of premium quality ABS plastic. Moreover, the housing of the equipment should be waterproof or dustproof. Ensure to know the type of material used to manufacture the device before making the purchase. 

Ingress Protection Rating:

It is a set of international standards related to the ability of the device to protect against the intrusion of foreign bodies. You can find it in the form of IP followed by a two-digit number, which is IP##. The first digit is applicable for solid, while the second digit of the number is for liquid. More the digit, the higher the level of protection for the equipment. 


A hygrometer is a portable device that measures the water vapor or humidity in the air. The equipment functions as a temperature and humidity data logger. You can purchase the device to measure or track humidity in various settings. The major primary applications of the device include weather observation and measuring indoor conditions. Hopefully, this guide equipped you with the knowledge of the hygrometer device.

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button