09/12/2022

5 Best Hygrometers for Measuring Humidity

Monitoring climate conditions is important for many industries, for both the comfort of their staff and clientele, storing goods and carrying out processes. Humidity plays a big role in this. Too high and moisture can damage products and negatively impact health; too low and dry air will cause skin and eyes to become irritated.

Keeping track of both temperature and humidity using hygrometers makes it easy to see when adjustments need to be made to prevent discomfort and damage.

How is humidity measured?

Humidity is the level of water vapour or moisture in the air. Humidity is usually measured using relative humidity, also known as %RH. It is measured on a scale of 0 to 100%RH.

100% refers to the maximum amount of water that can be present in the air at the current temperature. So if a hygrometer measures 50%RH, the air currently contains 50% of the maximum amount of water it could contain.

Warmer air can hold more water vapour than cool air.

What device is used to measure humidity?

Humidity is measured using a hygrometer. These humidity measurement devices display the relative humidity (%RH) and air temperature (°C/°F). Some hygrometers also display the dew point.

What is the dew point?

The dew point is the temperature at which water vapour will turn into a liquid form, whether this is condensation, fog, rain or snow. When the air temperature and the dew point temperature are equal, the relative humidity will be 100%RH. This is because the air is holding the maximum amount of water vapour it can at the current temperature.

A decrease in temperature will make the dew point go down because the air can hold less vapour at colder temperatures. So, for example, turning the heating on will increase the dew point and decrease the risk of condensation inside the home.

The dew point is a good indicator of how muggy the atmosphere will feel.

Why is humidity important?

High or low quantities of water vapour inside buildings can damage human health and the storage of goods such as wooden construction materials, food products, pharmaceuticals, fuels, paper, and electronic components.

High humidity (above 70%RH) causes dampness and condensation, leading to mould and dust mites. Humidity levels below 25%RH can cause respiratory discomfort.

Regularly monitoring relative humidity in buildings using a hygrometer enables users to maintain a healthy humidity level. This can be done by opening windows, adjusting heating settings or using humidifiers and dehumidifiers.

Hygrometer accuracy and sensor calibration

After a period of use, hygrometer readings are prone to drift. This is where the readings become less accurate, which can be identified by a calibration test.

Creating controlled humidity conditions to validate the accuracy of a hygrometer is more difficult than with temperature. The best way to check hygrometer accuracy is by sending it to an accredited humidity laboratory for testing. If the readings are inaccurate the laboratory can recalibrate it.

At ETI, we have an in-house UKAS-accredited laboratory for humidity and temperature calibration. Many of our calibrated humidity meters are available with 3-point UKAS certificates, so you can be confident your readings are accurate.

To calibrate your humidity sensor, send it back to us for recalibration. It will be returned to you with a new UKAS certificate.

Best hygrometers for every application

Find the best hygrometer for your home or business below.

Best hygrometer for HVAC professionals

The 6100 and 6102 ETI Therma-Hygrometers are the best hygrometers for measuring temperature and humidity on the move. Ideal for HVAC professionals who need to transport their equipment between multiple sites during the day, the 6100 and 6102 Therma-Hygrometers are easy-to-use instruments with accurate measurements.

These Therma-Hygrometers display the temperature, relative humidity and dew point, with max/min functions for each. They feature interchangeable wired probes and are available with an optional 3-point calibration certificate.

Shop the 6100 and 6102 Therma-Hygrometers.

Best temperature and humidity meter for engineers

The 6000 and 6002 ETI Therma-Hygrometers have all of the great benefits of the 6100 and 6102 models, with the addition of a fixed temperature and humidity probe for easy one-handed operation.

Designed for engineers and other professionals who need a portable hygrometer with a fixed probe, these accurate hygrometers feature robust cases and long battery lives of up to five years.

Shop the 6000 and 6002 Therma-Hygrometers.

Best thermometer hygrometer for building applications

The ETI Therma-Hygrometer for panel mounting is ideal for building professionals and OEMs who need to measure the humidity inside a container.

Building professionals can mount the hygrometer onto an insulated box to check the humidity above a freshly screeded or concreted floor, ensuring it is dry enough to lay a wood floor on top. OEMs may use a panel-mounted hygrometer for installing into equipment like vivariums and incubators.

Featuring a screw clamp, this Therma-Hygrometer is easy to install and read.

Shop the Therma-Hygrometer for panel mounting.

Best for hygrometer for storage, workplaces and homes

The ETI Comfort Thermometer is the best hygrometer for consistently monitoring the temperature and humidity in any indoor space to ensure they are at optimum levels.

Featuring a clear colour-coded bar, users can quickly and easily check whether the room is cold, comfortable or hot.

This is ideal for humidity control in manufacturing, homes, and workplaces where comfort is essential. It can also be used to monitor the humidity of paper storage, wine storage humidity and storage of other goods such as wood and pharmaceuticals where moisture levels are critical.

Shop the Comfort Thermometer.

Best thermo hygrometer for hydroponics

The Therma-Hygrometer with remote probe and alarm is perfect for the hydroponics industry and growing and gardening.

The remote probe can measure the water tank feeding the plants or the outdoor temperature, while the internal sensor measures the ambient temperature and humidity of the grow room, greenhouse or building.

The Therma-Hygrometer will alarm if the temperature drops below 0 °C so horticulture professionals can prepare for frost.

Shop the Therma-Hygrometer with remote probe.