A hygrometer is a device that will measure humidity in the air. There are many different types of hygrometer, but they all work roughly the same way, providing humidity readings for its user. With all the various types of humidity meters in the industry, humidity and temperature levels can be determined with varying levels of accuracy. Different humidity monitors are used for different industries, but at the end of it, they are all measuring humidity regardless of the type of hygrometer it is.

Generally you’ll see either a mechanical or digital hygrometer being the main two options on the market. Mechanical hygrometers use a hair or string to measure the moisture content in the air. The hair or string expands when it comes into contact with water vapor, and this expansion is used to calculate the relative humidity. Electronic hygrometers use sensors to measure the moisture content in the air. These sensors can be either digital or analog. You’ll find that a digital humidity meter will be able to provide humidity readings with greater accuracy than a manual humidity gauge. This isn’t due to the hygrometer having a different temperature range or anything like that; but rather because manual temperature readings are prone to human error.

Humidity readings are important in a lot of industries. A hygrometer is the best tool for measuring humidity regardless of what industry you’re in. A hygrometer can be used to provide accurate readings which will help weather forecasters predict precipitation. A humidity monitor is also great for farmers so they can measure humidity in their crops as it can impact the growth and yield of their crops. Another example of hygrometer usage in the industry are manufacturers. Depending on their product, humidity levels may actually prove to be vital for storage or for other aspects of the product. They can use a hygrometer to monitor humidity to ensure that their products are consistently meeting the same standards, and a humidity monitor can be set up to ensure a controlled environment as well. No matter what industry you’re in, a hygrometer can be a valuable tool for measuring moisture content. However, you’ll find that a hygrometer is also great for personal use, and actually has a lot of usage at home as well.


A hygrometer measures the amount of water vapor in the air. It is important to know the humidity level in your environment because it can affect your skin, health, comfort, and ability to work. The ideal range of humidity for human beings is between 30 and 50 percent.

As mentioned previously, there are many variations of the classic hygrometer on the market, but they all operate on the same principle: they measure the amount of water vapor in the air by measuring the air’s capacity to hold moisture. The most common type of hygrometer is the psychrometer, which uses two thermometers to measure both dry-bulb temperature and wet-bulb temperature. The wet-bulb temperature is measured by putting a thermometer’s bulb in a cloth sleeve that is moistened with distilled water. Evaporation from the wet cloth cools the thermometer’s bulb, so the wet-bulb temperature is lower than the dry-bulb temperature. The difference between the two temperatures is called the wet-bulb depression, and it is used to calculate the relative humidity. For example, if the air temperature is 75 degrees Fahrenheit and the wet-bulb temperature is 72 degrees Fahrenheit, the relative humidity would be 60 percent. A hygrometer can also do more than just provide relative humidity level, some can measure both temperature and humidity simultaneously. With fancier ones, you can get separate temperature measurements and even have add-ons such as remote monitoring. Most modern hygrometers will provide extremely accurate readings within a specific temperature range, and depending on your relative humidity in the area this may impede accurate measurements.
Thermopro TP357 Bluetooth Digital Indoor Hygrometer Thermometer

Types of

Analog/Mechanical Hygrometer

These are also known as hair tension hygrometers, where they make use of the principle that fine substances such as human hair will contract and expand in response to the humidity level. Although less accurate than a digital hygrometer, mechanical hygrometers are some of the most affordable hygrometer options on the market. They also have a wide humidity range and can usually provide a temperature reading as well. Another thing to note is that in this type of hygrometer, you also have to rely on reading the humidity gauge manually rather than getting an exact relative humidity value. Depending on your needs, this might be all you need to measure humidity and might even be perfect for a home hygrometer. However, if you’re looking at something a little bit more sophisticated for your wine cellar or other confined spaces – you might want to take advantage of options such as data storage also.

Digital Hygrometer

A digital hygrometer offers higher temperature accuracy and will also usually have a wider humidity range. It can perform functions such as measuring ambient temperature, acting as a humidity meter and depending on the model – it might even be able to link to digital devices. The biggest benefit of these hygrometers is that they provide data storage, have a long battery life without any sacrifice to the data logging or humidity meter function. However, these may require tuning and calibration to the ambient air to ensure that tracked humidity changes are accurate. Fortunately for you, most hygrometers come with a calibration kit so that you can measure your home’s humidity levels accurately and easily!

Types of

It’s critical to stay on top of the humidity readings in your house. Humidity, or the amount of water vapor in the air, can have a significant impact on not just your and your family’s health but also certain favorite hobbies. For that reason, you should consider getting yourself a humidity monitor, otherwise known as hygrometers or a humidity meter. Understanding and adjusting your home’s heating and ventilation can benefit your sinuses greatly, allowing passageways to remain clear and making it easier to breathe. In fact, numerous studies have shown that relative humidity monitor has a significant impact on a variety of health problems. For individuals who have been advised by their doctors to maintain a controlled humidity, monitoring humidity is especially crucial. Measuring humidity readings is also critical in non-health situations like wine and cigarettes when it comes to things such as cheese. You might want to consider getting humidity control, humidity monitors or anything that can provide relatively accurate measurements especially if you require a certain relative humidity for your health. You’ll find that a humidity meter or humidity monitor also work as a temperature monitor as well. There are also other type of thermometers like food thermometer and cooking thermometer. Instead of guessing the current humidity in your house, invest in a digital humidity meter or a humidity monitor with a humidity gauge so that you can get a general sense of the ambient air. The best hygrometers are capable of detecting both temperature and humidity in the air. Either way, you’ll want to make sure that you’re within a certain humidity range for daily comfort. Just as you prefer a certain temperature range inside your house, you’ll want to measure humidity regularly to maintain the level you want.

Types of Hygrometers

Hygrometers come in a variety of forms, but they all involve detecting and displaying the humidity level in a given area. Dew point hygrometers and psychrometers are worth learning about to understand the science behind these devices, which are increasingly popular. Keep in mind that many hygrometers also show the temperature range, which can be quite useful in food storage locations or wine cellars. You’ll also have to choose the right type for your usage, as there are a variety of humidity meters for different environments, like capacitive hygrometers vs resistive hygrometers, wet bulb thermometer vs dry bulb thermometer, cigar humidors and so much more depending on what you require from your hygrometer. You’ll also find that some are a lot more accurate, but may have a higher price whereas others are for more specific purposes like a cigar hygrometer.


Electrical hygrometers are the most widely used hygrometers humidity sensor on the market today, and they’re also among the most high-tech. These instruments read changes in electrical resistance across a semiconductor or sensor caused by air moisture content. As the moisture level fluctuates, it raises or lowers the resistance, which is shown on the meter. This is a relatively accurate hygrometer, and works well for a controlled environment. Today, the majority of electrical hygrometers run on batteries. Many models have Bluetooth connectivity and allow you to check the readings of your hygrometer from other devices such as your phone, allowing you to access readings anywhere in your house.

Mechanical Hygrometers

A mechanical hygrometer is a commonplace sight at a kid’s science fair. This popular science experiment displays humidity by monitoring the changes in organic substances caused by moisture content. This definitely doesn’t provide accurate results, as there is no true measurement, rather it’s more of a relative measurement. Mechanical hygrometers work on the same principle as thermometers. A needle pointing to a humidity scale is controlled by organic materials like ox gut or human hair, which absorb moisture from the air and contract and become heavier when wet, raising the needle. As the air dries, the material becomes lighter and less dense, allowing the needle to fall. This gives a general idea of how humid the area is, but isn’t very accurate.

Dew Point Hygrometers

Dew point hygrometers have polished metal mirrors on which water condenses. Experimenters may determine the dew point by noting when water begins to condense on the mirror while monitoring air temperature at which this happens. To get accurate readings, these instruments need extremely constant conditions, such as constant atmospheric pressure and constant vapor content to get the most accurate results. Most hygrometers do not require this level of control in this day and age, but at one point they were used quite often. The first dew point hygrometer was invented in 1751. They aren’t used anymore, but modern hygrometers are indebted to this early instrument in some way.


In most kitchens or greenhouses, you won’t find psychrometers. They’re still in use today in meteorology. They’re also quite popular among wildland firefighters for detecting the risk of a fire and estimating how serious it may be. This consists of a wet bulb and a dry bulb thermometer, and the difference between the two is used to determine humidity changes. To determine the relative humidity, psychrometers use two thermometers. It’s a little more technical than that: one thermometer is wrapped in a damp cloth and spun, while the other is not. The experimenter then enters the readings from the thermometers into an equation to calculate the humidity level.

What to Look for in a Hygrometer When Shopping

Choosing the finest hygrometer for your needs is a difficult task. The place and manner in which you intend to use your new hygrometer, as well as simplicity of use and battery life, are all important factors to consider. You’ll want to consider a variety of factors such as how accurate you need your measurements to be, the range it works in as well as the general temperatures you’ll be looking at.

Applications of a humidity monitor

When selecting a hygrometer, the application for your instrument makes a major difference. For example, if you’re monitoring humidity levels in a greenhouse, you may wish to use a different product than if you’re checking on the humidity inside a reptile tank. Obviously the temperature that you’re looking for will be different, and this might mean you need different sensors, and you might also have to consider condensation. A digital hygrometer on a bookshelf or table will suffice for most situations. However, if you need a tiny hygrometer or one that works without the need of a battery for specialized requirements and applications, you may want to look elsewhere. Before purchasing a hygrometer, consider your needs carefully.

Accuracy of humidity readings

Hygrometers are generally trustworthy and consistent instruments. The majority of them are within 5 percent error. Ensure that the hygrometer you’re buying works within this range to ensure you receive a good one. Calibration is subsequently required to achieve accuracy beyond that. If you suspect your hygrometer’s accuracy is off, you should calibrate it. A hygrometer calibration kit involves putting your hygrometer in a sealed bag for a specific length of time. If the percentage measured by the kit differs from the relative humidity reading, you will need to calibrate it using the chart that accompanies the kit.

Digital vs. Analog humidity meter

The usefulness and how much you like using your hygrometer are both factors to consider. The fantastic debate between digital versus analog thermometers has begun. An analog hygrometer is hard to beat when it comes to reading your hygrometer from a distance. These physical hygrometers have needles that point to the general range on the dial, which is all you’ll need in most cases. An analog dial has the disadvantage of being difficult to read exactly. It’s also difficult to compare readings on analog dials if you’re monitoring different areas. When it comes to monitoring humidity levels, digital displays are the way to go. If the moisture level begins to change, you’ll notice it sooner and more easily with a digital hygrometer’s numerical display. The figures will alter rather than tiny needle movements. The disadvantage is that low-quality or small digital displays can be difficult to read because of the small font.  The digital thermometers are good to get easiness in your work.

Power Source and Battery Life

If you’re using an electrical hygrometer, you’ll need to select the correct power supply for your needs. Generally a digital hygrometer will rely on electricity, and there will be detailed instructions on how to power it up. There are several countertop-style hygrometers that include a 110-volt electrical connection and may be plugged into the wall. You can also choose between battery operation and 110 volts of electricity. Battery life may be more important if you’re using a remote Bluetooth-enabled device. If you’re keeping an aquarium that you’d like to keep closed as much as possible, for example, get a sensor with a long battery life. Some versions use rechargeable batteries, which can be really helpful since the battery lasts for a long time.

Remote Monitoring and Alerts

Humidity levels are not always about personal comfort or convenience. It’s possible that a favorite pastime or interest necessitates their monitoring. Monitoring the humidity in your wine cellar, for example, or that of your cigar humidor might be the difference between keeping a fantastic collection and ruining an expensive one. For help keeping these areas within a crucial humidity range, it’s worth purchasing a hygrometer that you can check from your smartphone or a remote display. Most importantly, perhaps, is that several of these devices will allow you to set a particular range and send you alerts when the humidity is outside of that range. Thanks to that alert, you may be able to take action and save your cache before it spoils or molds.

Interconnectivity and User Interface

You can connect a hygrometer with your personal technology in a variety of ways thanks to improvements in Bluetooth, WiFi, and smart home technology. Many of these gadgets have their own apps, allowing you to keep track of your humidity levels using Bluetooth from your phone. This can be really useful when attempting to avoid potentially damaging a sensitive environment such as a greenhouse or terrarium. However, keep in mind that not all applications are created equal in terms of usability and functionality.

Data Logging

If you’re serious about keeping your house at a reasonable humidity level for health reasons, hobbies, or any other reason, you’ll need to collect data with your humidity meter. A hygrometer that can measure humidity levels and temperatures might be helpful. You may keep track of your data and stay ahead of seasonal or environmental changes by monitoring the humidity in your home more often. Keeping track of your usage is a lot easier with apps on our list. Some devices, for example, store data logs in their programs, so you’ll have access to up to two years’ worth of information. More significantly, you may generate a spreadsheet of this critical information and save it on your computer or print it out.
how to get indoor humidity readings

FAQs About Your New

I’m sure you must still have a fair bit of questions about humidors and hygrometers. This section is a compilation of the most frequently asked questions about hygrometers and the corresponding answers. If you still have questions after reading this section, you can reach out to your hygrometer manufacturer’s customer service department for more detailed answers.

A main living area is usually the best place for a hygrometer. Moisture created by a kitchen or bathroom can throw off the readings, so it’s best to keep your hygrometer in a drier space like a living room or office. You’ll want to place it in an area that is representative of your whole house, and not somewhere where condensation is likely to build up or somewhere that is known to have low humidity.

Using a calibration kit, you can determine how far off your hygrometer is before calibrating it. Analog hygrometers have adjustment screws in the back of the gauge that you can manipulate to adjust the reading. Digital thermometers have adjustment knobs that you can dial in to the humidity you want. You want to always calibrate your measuring device so that you can increase your accuracy.

If you need to add some moisture to the air, you can use a humidifier, which emits water vapor into the air. If you need to decrease your humidity levels, a dehumidifier will help. These machines pull air in, remove the moisture, and release the drier air into the environment.

Outside of calibration, there are easy ways to check if your hygrometer is working. You can place it in an airtight container along with a bottle cap full of salt with a splash of water. After several hours, you should notice a difference in the hygrometer’s readings. You’ll want to double check your humidity measurements once in a while just to ensure that you’re still getting accurate measurements and that you don’t need to replace your device yet.

Ready to buy a

Luckily for you, ThermoPro has many hygrometer options available for you. From a simple digital hygrometer to something a little more sophisticated in terms of temperature and humidity measurements, we have you covered. We also have meat thermometerInstant read thermometer and indoor thermometer.

Come talk to us today to get your very own digital hygrometer!
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