Archive: Feb 2022

Absolute Humidity vs Relative Humidity

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Moisture analysis involves the process of measuring moisture and humidity in a particular environment. In general, humidity refers to the amount of moisture in the air; however, humidity can be measured in two ways: absolute and relative. Absolute humidity and relative humidity measurements are crucial in a wide range of applications from HVAC and drying processes to refining oil and creating sensitive pharmaceutical products. Understanding the differences between these two measurements will ensure that you are collecting the right moisture analysis data for your application.

Absolute vs. Relative Humidity

What Is Absolute Humidity?

Absolute humidity refers to the measurement of water vapor within a given volume of air. 

To determine absolute humidity, the mass of water vapor is divided by the mass of dry air within a specific volume of air at a given temperature. This measurement is expressed in grams of water vapor per cubic meter of air (g/m3).

Absolute Humidity can also be expressed as the percent moisture by volume of air. 

What Is Relative Humidity?

Relative humidity is typically expressed as a percentage and refers to the amount of water vapor in the air, relative to the maximum amount of water vapor that could be present in the air at a given temperature. It indicates the actual moisture content compared to the potential moisture content of the air. 

For example, relative humidity of 50% indicates that the water vapor in the air is half of the amount that could potentially be present in the air at complete saturation. Temperature is essential to measuring relative humidity because the maximum water vapor content of an air mass increases or decreases with temperature. A warm air mass can be mixed with more water vapor than a cool air mass of the same size.

Absolute Humidity is independent of temperature while relative humidity is a function of temperature.

Rely on MAC Instruments for Moisture Analysis

Absolute humidity and relative humidity are different methods of measuring air moisture content. Since moisture analysis is crucial for a wide range of industries and applications, it is important to have reliable moisture analysis equipment to ensure precise and accurate measurements. At MAC Instruments, we have been delivering high-quality moisture analyzers since 1990. Our equipment is capable of measuring absolute humidity in even the most extreme temperature situations. Our available moisture analyzers include:

  • Mac 155 Moisture AnalyzerMAC 125. The MAC 125 comes in digital and analog models and uses no chemicals, wet bulb techniques, compressed air, optics, or mirrors. Instead, it uses a solid state humidity measurement process to ensure accurate measurements even in extreme operating environments.  
  • MAC 155. The MAC 155  is the ideal solution for monitoring stack emission moisture for EPA regulations.
  • MAC 116. The MAC 116 delivers steam analysis for food preparation environments. It has been used in meat and poultry processing conveyor ovens since 2011 and can be installed in most ovens with a standardized and easy to sanitize design.

The easy-to-use moisture analysis tools offered by MAC Instruments are waterproof and resists high temperatures up to 1200 °F. 

To get started on your moisture analysis solution, request a quote from our team of experts today.


(Click to Expand Infographic)

Absolute vs. Relative Humidity infographic