How Do Humidity Sensors Work?

Pippa Boothman -
humidity sensors, water, IoT
Illustration: © IoT For All

Humidity sensors are electronic devices that measure and report the moisture and air temperature of the surrounding environment where they are deployed e.g., in air, soil, or confined spaces.

Humidity measurements indicate the concentration of water vapor presented in the air. They provide their measurements in the form of a proper electronic signal. Moreover, they also report relative humidity, i.e., the moisture ratio to the maximum moisture at a given temperature.

The relative humidity is useful for many applications, like HVAC (Heating Ventilation Air Conditioning) and comfort optimization applications in Smart Buildings and Facilities Management.

State of the art humidity sensors provide support for internet connectivity and can be flexibly deployed in the Internet of Things (IoT) applications. This facilitates the integration of humidity measurements with the output of other sensors (e.g., temperature sensors) and boosts IoT applications intelligence in various industry applications.

A humidity sensor’s quality is reflected in its accuracy, reliability, response time, longevity, security, robustness, and ease of deployment. These characteristics also determine the sensor’s cost. Furthermore, they drive the selection of humidity sensors for different applications.


Humidity sensing enables a host of value-added Applications in various industries, including cold storage management, comfort optimization, asset condition tracking, and remote monitoring.

Humidity Sensors in Cold Storage Management

In cold storage management, humidity sensing ensures proper storage conditions for temperature-sensitive products such as food, beverage, and pharmaceuticals.

Humidity sensors contribute to regulatory compliance and to automating the auditing of the status of the equipment. In conjunction with temperature sensors, they also contribute to increasing product safety, while reducing waste.

Overall, the combination of temperature sensors and humidity sensors in cold storage management enables the development of powerful regulatory compliance tools, automation of audits, increased product safety, and improved environmental performance.

Humidity Sensors in Smart Buildings & Facilities Management

In smart buildings, humidity sensors are deployed to improve the comfort offered to tenants and occupants. For example, they provide insights on certain rooms’ moisture conditions, which can subsequently drive the fine-tuning of the rooms’ conditions through the Building Management System (BMS).

By adding humidity sensors to HVAC systems and office environments, Facilities Managers can efficiently monitor, measure, and adjust humidity to provide a comfortable and productive working environment. In many cases, humidity sensors enhance temperature monitoring functionalities towards increased comfort and fine-tuning of energy consumption.

Beyond comfort, humidity sensing is essential to ensuring proper conditions for valuable assets. For example, galleries, museums, and art collectors can maintain stable environmental conditions for their collections. For this purpose, they should keep track of humidity changes, as moisture can be catastrophic for paintings, drawings, prints, mosaics, and sculptures. Humidity monitoring helps galleries and museums protect their assets and lower their insurance costs.

Humidity Sensors in Remote Monitoring and Intelligent Asset Management

Humidity sensors are also integral elements of remote monitoring and intelligent asset management Applications. They can be deployed on assets (e.g., pumps, compressors, fans, data centers) to facilitate a transition from preventive to predictive maintenance.

Specifically, humidity sensor data streams can enhance the accuracy of predictive analytics for condition-based monitoring. They also enable the real-time monitoring of humidity to identify problems (e.g., potential leakages) before they occur. In these ways, humidity sensors extend the lifetime of critical assets and maximize their overall efficiency.

In many cases, humidity sensing is used in conjunction with other sensing types (e.g., temperature, proximity, touch, water) to offer additional value-added services in smart buildings and facilities management contexts. Complete sensing solutions help set Facilities Managers apart from their competitors.

Pippa Boothman, Disruptive Technologies

Guest Writer
Guest Writer
Guest writers are IoT experts and enthusiasts interested in sharing their insights with the IoT industry through IoT For All.
Guest writers are IoT experts and enthusiasts interested in sharing their insights with the IoT industry through IoT For All.