A hygrometer, sometimes known as a temperature and humidity monitor or humidity meter, measures the humidity and water vapour in the air. It does this by calculating both air pressure and temperature changes, which results in the moisture's percentage in the air. Used in environments that require constant monitoring of humidity, such as food processing where it's imperative that humidity stay at a constant as it could affect production.
Within a volume of air, the maximum amount of water vapour it can hold varies by temperature with cold air holding a fraction of what warmer air will. Most hygrometers for humidity use temperature to give the relative humidity (RH) for a particular temperature and display it as a percentage. Digital hygrometers have a built-in digital LCD display but there are several which use an analogue readout, these are primarily for continuous monitoring. Some offer additional features such as datalogging, web bulb temperature or dewpoint.
Some types of hygrometers include:
Used to test HVAC systems and office environments. They often feature a probe which can be inserted through an air-conditioning duct to get readings from within the ducting.
Offer a modern approach for easy-to-read measurements on a digital, typically LED screen, and sometimes feature an in-built data logger for recording measurements for analysis. Digital thermo hygrometers are available as resistive and capacitive, both have different methods to achieve accurate results.
When selecting a hygrometer, understanding its core features and specifications is crucial for obtaining accurate and reliable humidity and temperature measurements. Here are some key aspects to consider:
Data logging capabilities allow for the recording of historical data, while alarms can alert you when conditions exceed predefined thresholds. At the same time, connectivity options like Bluetooth or Wi-Fi enable a temperature and humidity monitor to be observed remotely and facilitate data transfer.
While both hygrometers and moisture meters are used to assess moisture levels, they target different mediums. A hygrometer measures the moisture present in the air, whereas a moisture meter measures the moisture content within solid materials like wood, paper, or stud walls. This distinction in application arises from their differing sensor technologies and units of measurement.
Hygrometers typically utilise capacitive sensors, resistive sensors, or thermal conductivity sensors to determine the amount of water vapor in the air. They commonly report this as relative humidity (RH), expressed as a percentage. Many temperature and humidity meter models will also display temperature and dew point.
In contrast, moisture meters employ electrical resistance or capacitance principles. These devices send a small electrical current through the material being tested; the meter then gauges the moisture content based on changes in the material's electrical conductivity. The results are usually displayed as a percentage by weight of moisture within the material.
Selecting the right hygrometer is essential for accurate environmental monitoring. Here are some common mistakes to avoid:
Accurate humidity and temperature monitoring, provided by reliable hygrometers, is critical across a wide spectrum of industrial applications, ensuring product quality, process efficiency, and the safety of sensitive environments.
RS is your trusted supplier and distributor of high-quality hygrometers in Australia. We offer an extensive range of temperature and humidity meter options, catering to all types of environmental test and measurement requirements. Our comprehensive selection includes reputable brands such as Testo, Extech, Rotronic Instruments, and many more. Whether you're looking to buy hygrometers for industrial processes, environmental monitoring, or HVAC applications, RS provides the products and support you can rely on. For more details on our ordering process, delivery services, and delivery fees, please refer to our Delivery page.