Building automation covers all applications in privately used living spaces, but also in office and industrial buildings. Small and large technical assistants ensure that living and working conditions are improved. Interlinked technical components reduce routine activities, they guarantee more safety and cost savings. Particular attention is paid to humidity and temperature sensors - here you can get a basic overview.
In buildings used for business and private purposes, intelligent devices are needed that switch themselves on or off at the right time as well as sensors that start these processes in the first place. Sensors are the sensory organs of building automation that convert sounds and perceptions into electrical signals. Everything is transferred to the system via the cloud and the smart technology is triggered. Sensors are often already integrated into the electronics, but can also be purchased independently in different types and sizes. The most common types used in and around buildings are included:
- Temperature sensor
- Sensors for measuring the air humidity
- Wind and rain gauge
- CO2 sensors
- Sensors for water leakage
- Motion detector
- smoke detector
- Contact sensors for windows and doors
- Noise sensors and presence detectors
Depending on the arrangement of the sensors, there are very different application scenarios. Humidity and temperature sensors play a special role in building automation.
A temperature sensor is an electrical or digital component that allows temperature to be measured via signals. Either the signal is sent directly or a message about the change of resistance is sent. Temperature sensors are often also called temperature sensors or thermal sensors. Whether refrigerator, coffee machine, stove, computer or heater - temperature sensors are omnipresent in everyday life and are available in different technologies and designs.
A lot has happened since the invention of the thermometer in the 16th century. In addition to thermistors, various thermocouples, thermopiles and platinum sensors, digital sensors are becoming increasingly important in temperature measurement. With an integrated circuit, these sensors convert the measured values of humidity and temperature into digital signals. Networking with computers, other smart measuring instruments and pre-programmed control elements allows the data to be read out directly.
While regular temperature sensors are found in household appliances, consumer electronics and medical technology, digital temperature sensors are mainly used in the smart home. The sensors control the heating and air conditioning to create or maintain a comfortable temperature, while at the same time optimizing energy consumption. In principle, the sensor measures either the temperature inside a device or the surface temperature. Of importance is how fast the sensor reacts, but also the quality between the matter to be measured and the sensor.
An important criterion for the selection of a temperature sensor are the reaction times. Some sensors request information only in a given interval and otherwise remain in the idle state. If a 15-minute scene has been created where the heating system lowers the temperature when a window is opened, it takes 14 minutes or longer for the sensor to perform its task, depending on the time of action. In this case, we recommend devices that remain active despite the idle state, react immediately to new information and make adjustments directly. The type of transmitter also plays a role, since completely different reaction times can be derived from the different technologies.
Infrared sensors measure the radiation emitted by a surface in the infrared range and derive the corresponding temperature from it. This sensor works without contact with the surface and has a much shorter reaction time than other sensors. A thermal equilibrium is not necessary for measurement, which is why the values of moving surfaces can be reliably determined. This predestines infrared temperature sensors for use on objects that are difficult to access. However, it should be noted that the measurement depends on the condition of the surface on the one hand, but also on the atmosphere of the distance covered by the sensor and the target object. Examples are dust or humidity. The detected measuring spot also increases with the distance between sensor and object. It must therefore be ensured that the size of the target and the distance between it and the sensor match.
Infrared sensors are calibrated with a black emitter, the so-called blackbody. In order to always provide reliable data, the calibration must be carried out in annual intervals. If the infrared sensor shows unreliable or wrong values, this can be a sign of overheating. The maximum ambient temperature limit must be observed. If the sensor is located in a very high temperature environment, water or air cooling should be considered to avoid destroying the technology. Infrared sensors can also undercool in combination with too high humidity. Moisture condensation occurs inside the sensor and water accumulates in the sensor, causing it to fail.
Optical sensors are suitable when many sensors have to be used or the distances between the individual measuring instruments are very large. Furthermore, optical sensors can be considered as an alternative to other technologies - especially when special application scenarios such as electromagnetic interference, strong magnetic fields or explosion hazard have to be considered. Here, conventional sensors usually fail quickly. As a rule of thumb, optical sensors are always profitable if more than 30 sensors are needed within an application. Optical sensors operate contactlessly, which means that the target object is not damaged. They can also be used with all materials and provide reliable data even at large detection distances.
It is usually not sufficient to control humidity or temperature with sensors. Checking the accuracy of the measured values at certain intervals is mandatory to ensure that the processes continue to run optimally. Aging of components, but also physical changes can cause so-called drifts. Before a sensor is put into operation for the first time, it is calibrated within a predefined specification. In order to detect drifts and determine the accuracy of the transmitted measurement data, a recalibration must be carried out at least once a year.
In a building, the climate is regulated by the flow of energy. All materials used for construction, but also the people working and living in a building, affect this energy flow, which has an indirect influence on the indoor climate. The installation of sensors has proven to be a reliable way of removing warm and humid room air. At the same time, cold outside air should not penetrate the building - the sensor becomes active when the dew point is reached at the worst component.
In order to keep people healthy and efficient, rooms should have an optimal air humidity. In many living rooms and offices, but also in bathrooms and toilets, this humidity is too high. In the worst case, too high humidity can lead to mold growth and long-term health problems. Humidity sensors help to keep the air humidity at the appropriate level of 45 to 60 %. The optimum value varies depending on the room and usage behavior. If a fan is equipped with humidity sensors, the moisture content of the air is automatically evaluated and reduced to the desired level.
Here, a stray field capacitor is located on the front of the sensor, which generates an electric field. The capacitor is influenced when the material to be measured passes through the electric field. With appropriate calibration the measuring signal is transmitted to the control units.
In short, plant sensors allow flowers in the garden to communicate with their owner. Measuring rods with sensors are placed in beds or deep pots on balconies and terraces near the root ball. All data is evaluated in a cloud and an interactive care assistant sends precise instructions tailored to the plant. This allows plants to be optimally cared for.
Do you have further questions about temperature and humidity sensors or are you thinking about comprehensive building automation in your house or office building? Then contact our team and we will be happy to advise you personally!