Air Humidity Meter

The following text is designed to assist you in purchasing an air humidity meter. However, should you have any questions about the air humidity meter products found on this website, please do not hesitate to contact the PCE technical support team at  or +44 (0) 2380 987 035 for PCE Instruments UK, or at  or +1 (561) 320-9162 for PCE Americas Inc.

Accuracy is a key component to consider when buying an air humidity meter. When looking at different air humidity meter devices, it is important to evaluate the air humidity meters based on the level of accuracy required for your application, as a high-accuracy air humidity meter product typically comes with a higher price tag. For example, a high-accuracy air humidity meter would be essential for a food safety inspector, as stringent standards must be met when it comes to food storage and refrigeration. In contrast, if you are in search of an air humidity meter for use in your home, a device with lower accuracy would provide you with an adequate estimate of the relative humidity indoors.

For temporary humidity measuring applications (such as simple control measurements, spot checks to assess concrete drying conditions, or evaluations of heating, ventilation and air conditioning (HVAC) system performance), a portable handheld air humidity meter without memory may be used. Portable air humidity meter devices often are ergonomically designed to allow for quick, easy and comfortable one-handed operation.

For long-term or continuous monitoring of relative humidity, a fixed air humidity meter with memory and data-logging capabilities is ideal. Many fixed air humidity meters with memory record and store date- and time-stamped humidity measurement data either to an internal memory or a removable SD memory card. Depending on the model, some air humidity meters for continuous monitoring also record and store peak values (minimum and maximum) and/or emit an alarm when a certain user-defined threshold of air humidity is reached. Most data-logging air humidity meters allow the stored data to be transferred to computer using special software, a USB or RS-232 interface cable and/or an SD memory card reader. Data transfer to a computer makes documentation and reporting easy, as measurements do not have to be written down by hand. In addition, some air humidity meter products save the data in a Microsoft Excel-compatible format.

Stationary air humidity meters used for the continuous monitoring of climate-controlled environments like refrigerated trucks, storage units, warehouses and museum archives are used to survey indoor environmental conditions in the context of safety and quality assurance. Air humidity meters with memory also aid in documenting an organization's compliance with industry standards and best practices. Air humidity meters for permanent installation usually come with the necessary brackets or hardware required for mounting the device on a wall or DIN rail. Often a fixed-installation air humidity meter instrument is equipped with a kickstand or tripod, so the device can be positioned as needed on a desk, table, counter or workbench. If it is necessary to read the humidity measuring results from a distance, an air humidity meter with a large and easy-to-read liquid crystal display (LCD) should be selected. In addition, when working in low-light or dark environments, it is critical that the display be backlit.

Again, application plays an important role when selecting an air humidity meter. For non-professional use, a simple air humidity meter that only needs to be switched on to start measuring is recommended. Most professional usages will require an air humidity meter with more advanced functions. Bear in mind, the more functions an air humidity meter possesses, the more complex the air humidity meter will be to use. However, experienced contractors, technicians and engineers will be more than comfortable using an air humidity meter with added functionality, as digital air humidity meter menu structures are somewhat standardized throughout the test, measurement and inspection equipment industry. If an air humidity meter has many different functions, it can be helpful to have several buttons or keys on the device, as more keys can provide time-saving shortcuts for navigating a device's menu structure. In just-in-time (JIT) manufacturing environments, even the smallest time savings can be a tremendous asset. Another point to consider regarding keys is their size. For example, in the food processing industry, bigger keys are desired to accommodate users required to wear protective gloves.

The air humidity meter's material and ingress protection (IP) rating are additional factors to explore before buying. Depending on the anticipated operating conditions, your air humidity meter may need to be made of a durable material such as high-quality ABS plastic. Your air humidity meter's housing also may need to be dustproof or waterproof. The IP rating system is a widely recognized set of international standards related to an electronic device's ability to protect against the intrusion of foreign bodies. This rating is typically presented as the letters I and P followed by a two-digit number, i.e., "IP##." The first digit of the number pertains to solids (dust), while the second digit pertains to liquids (water). The higher the digit, the greater the level of protection afforded by the device.

Lastly, don't forget to evaluate the air humidity meter's power supply and accessories. If your air humidity meter is powered by batteries, the batteries should be a commonly used size so they are easy to find and affordable to replace. If your air humidity meter is powered by an AC adapter, take care to ensure the power cable won't interfere with other aspects of your work environment. Many PCE-brand air humidity meters offer replacement parts like spare batteries, sensors, cables and adaptors as optional accessories. In addition, an ISO calibration certificate can be obtained as an accessory for most PCE-brand air humidity meter products.

In modern measuring technology, an air humidity meter often is used in combination with a temperature measuring instrument. The measured values for relative humidity and temperature can be used to in tandem to measure dew point or water vapor content.

Humidity, also called relative humidity or air humidity, is defined as the amount of water vapor in the air. However, humidity is relative. It is normal and even important that air contains water vapor. The amount of water vapor in the air depends on several factors, including the temperature of the air. Warm air is generally more humid than cold air. This means that when air temperature decreases, the maximum amount of water the air can hold also decreases. An air humidity meter displays readings in a percentage of relative humidity (% RH). So, if an air humidity meter displays a measuring result of 20% RH, then the air holds 20% of the maximum amount of water possible at that temperature.

When the air is humid outdoors, water and sweat evaporate more slowly. Fog, dew and precipitation become more likely. Indoors, high humidity can trigger symptoms for those suffering from allergies, asthma and chronic obstructive pulmonary disease (COPD). Excessive condensation also can form in overly humid indoor environments, resulting in the growth of mold and bacteria. However, when the indoor air is too dry, skin becomes itchy and dry and can even crack. Some people also experience problems with nose bleeds in very dry climates.

When the air is too humid indoors, it can sometimes be enough to simply open some windows and doors. Other times, the performance of the HVAC system should be evaluated by a trained professional. In extreme cases, a more complex measure must be taken, like the installation of an extractor fan. In many instances, a reliable air humidity meter can be used to identify the root of the problem.

The durability and shelf-life of many materials depends on the climatic conditions in the storage room. Too high air humidity as well as too low may be harmful and cause damage to the stored goods. In order to protect the high-quality and sensitive goods, temperature and humidity at the storage place should be monitored with a humidity measuring device and adjusted if necessary. If the set limit values are exceeded, some of the humidity meters can trigger alarms or automatically switch on the devices for ventilation, temperature control, dehumidification or air humidification. Before storing, it must be clarified what temperature and humidity requirements for the particular materials to be stored should be met. If different materials with different requirements are to be stored, it is recommended to select and prepare separate storage rooms according to the requirements. The foodstuffs that are to be processed in the canteen kitchens, for example, have very different requirements in terms of temperature and humidity. While flour, sugar, salt and nuts need to be protected from excessive humidity, freshly harvested foods that have not been specially preserved, such as potatoes, vegetables, salads and some types of fruit, require a rather high relative humidity. Since the fruits themselves contain a lot of water, they lose their taste and consistency when moisture is released into an air that is too dry.
Humidity meters are also important for monitoring the indoor climate in warehouses for raw materials and end products in the production companies so that electronic components, paper, textiles and corrosion-resistant metal parts do not become unusable because of incorrect storage conditions.

In many professions, people spend most of the day in the same room. The climate there is important for the well-being and thus for the performance of the employees. Important factors for the indoor climate are temperature, humidity, air speed and heat radiation. Temperature and humidity can be checked with a simple humidity meter that also displays the temperature.
However, the perception of temperature, like outdoors, is influenced by the air speed, air humidity and heat radiation. To assess the room temperature, it is not enough to simply measure the air temperature. The temperature resulting from the air temperature and the average radiation temperature of the room enclosing surfaces is called the operative room temperature. It can be determined from the air temperature and the surface temperatures of the walls and ceilings or with the help of a special thermometer, the globe thermometer or black globe thermometer. Air speed and humidity also have an effect on the temperature regulation of the body via skin and thus on the sensation of warmth. If the air temperature is lower than the body temperature, higher flow rates lead to a faster cooling of the body, which is usually desirable in hot weather. However, high humidity hinders the body's heat regulation through sweating. For physiological reasons, the values for the maximum relative humidity are specified in the technical rules for workplaces ASR A3.6. The permissible value is 80% at 20 ° C air temperature, 70% at 22 ° C, 62% at 24 ° C and only 55% at 26 ° C air temperature.
There are humidity meters for indoor climate measurements that are equipped with a sensor for measuring the flow velocities and other special devices with functions for assessing the heat stress load.
Also high levels of carbon dioxide and pollutants in the indoor air affect the ability to concentrate in the workplace and can lead to health problems. The values for carbon dioxide, formaldehyde and volatile organic compounds can be determined with inexpensive measuring devices. Many of these environmental measuring devices simplify the evaluation of the measurement results by giving optical or acoustical signals that the limit values have been exceeded. Then one may reduce the pollutant content in the room air, for example, by targeted ventilation.