Humidity Measuring Equipment And Devices (Hygrometer, Humidistat)

What Is Humidity

This is the amount or level of water vapour in the atmosphere. Since water molecules are much lighter than air, moist air always rises above dry air. There are plenty of ways that moisture gets into the air such as evaporation, atomization or by turning into extra fine particles.

For most people, humidity is not an issue when is at the preferred levels. But for others, high and low humidity extremes can have adverse effects on both the environment and your health as well.

This is why it is very important to measure and monitor humidity levels to ensure that they remain at optimum levels. Before we get to how to measure humidity and the instruments used, let’s look at measurement types. There are three primary measurements of humidity.

Absolute Humidity

This is a measure of the actual amount of atmospheric water in the air no matter what the temperature is. The units used are grams of vapour per cubic meter of air. The higher this amount, the higher the absolute humidity measurement.

Relative Humidity

Typically expressed as a percentage, relative humidity can be referred to as the amount of water vapour currently in the air as compared to the actual or full amount it can hold at a certain temperature.

Warm air contains significantly more moisture than cold, freezing air. For example, if the relative humidity in your home is 50%, then this means that the room is halfway saturated with vapour.

Specific Humidity

This is the actual weight of atmospheric water contained in a unit weight of air. This measurement is expressed using grams of vapour per Kg of air and is often referred to as the humidity ratio.

Humidity Measuring Equipment And Devices

There are two main types of instruments used to measure humidity. These include:

1. Hygrometer

hygrometerA hygrometer is one of the most common humidity measuring instruments found in almost every home. This device work on principles of mass, pressure, temperature, electrical or mechanical changes in the environment or material to measure levels of water vapour in a room. There are generally two types of hygrometers.

  • Analogue Hygrometers – these use a moisture-sensitive material attached to a coil spring to determine humidity levels. The spring then controls a needle on a dial that is super easy to read.
  • Digital Hygrometers – establish relative humidity using a sensor for the purpose of monitoring electric currents affected by atmospheric moisture levels.

A few years ago, people used less advanced and classic devices like Psychrometers, hair tension hygrometers, dew point hygrometers, metal, and paper coil hygrometers. Fortunately, technology has caught up with us and allowed for more advanced instruments like thermal hygrometers, resistive hygrometers, capacitive and gravimetric hygrometers.

2. Humidistat

humidistatA Humidistat is another tool used to measure the relative humidity levels in the atmosphere. In many cases, this device is sold as part of an entire unit that can not only monitor humidity levels, but significantly influence them as well.

If you have a humidity problem, you can choose to buy a humidistat within a humidifier to increase moisture levels, or a dehumidifier to reduce it.

While this electronic method of measuring and controlling humidity levels might be a bit more pricey that your average hygrometer, the added benefits are well worth the extra coin.

How To Measure Humidity Without A Hygrometer

If you don’t have or don’t want to buy hygrometer or humidistat, you still have few options:


Like most people, you probably take humidity for granted and don’t take the time to realise how dangerous it can be until it is too late. Do not wait until the damage becomes irreversible. Too much humidity can be just as hazardous as too little.

On the high side, humidity always leads to dampness and breeding of mould and mildew around your home for which you will need to buy an air dehumidifier. If the levels get too low, dry air can wreak havoc on the inhabitants’ respiratory systems.

Leaving this issue unresolved can not only cause adverse effects to your family’s health, but also threaten the integrity of your home and furniture as well. This is why measuring the humidity levels in your home is of the utmost importance.

However, it could prove worthless if no steps are taken to rectify the humidity to optimum levels. If you have not been paying any mind to the humidity levels in your home, make sure you get a humidity monitoring device today and keep your family out of harm’s way.

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