Basic information about the sensors
Have you ever wondered what sensors do you need for your next project? What is the difference between passive or active temperature sensor? What is the standard output signal? What is the most used power supply? We would like to present you with a basic guide about various sensor types, how they work, and what are they mostly used for. In addition to that, we would also cover some basic information about advanced protocols which are used as main industry standards and most importantly, where can you get all those sensors in one place.
Before telling you everything you need to know to start to understand how does the sensor work we would like to give you a hint of what we would cover below:
1. What kind of sensors are available in today’s market?
Let’s start with the basics. The sensor can be put into several different groups or categories. The main groups are the temperature, humidity, CO2 and air quality, motion and light, pressure, flow, meteorology and weather stations, and their accessories (immersion sleeves, mounting flange,…).
Temperature sensor is most common one and can be installed as a passive or active version. What’s the difference? The passive sensor uses various thermocouples, such as Pt100, Pt1000, NTC3k, LM235Z, etc., to measure the temperature. It’s the simplest temperature sensor available. The active sensor on the other hand have a standard thermocouple, mostly Pt1000, to measure the temperature but it convert those measurements into a standardized output signal 0-10V or 4-20mA.
What are the advantages of active sensor over passive one? Mostly they are much more user-friendly and provide a selection of different measuring ranges while their accuracy is very good. Some of the advanced options support also manually set „offset“ using the potentiometer.
Humidity sensor is much more expensive than temperature sensor because they measure temperature and humidity as well. They are usually modified by DIP switches to set the different measuring ranges, relative humidity, absolute humidity, dew point, enthalpy, and mixing ratio. So do you need an additional temperature sensor if you use a humidity sensor? No. The humidity sensor always measures the temperature so the additional temperature sensor is not needed if the sensor is installed in the same room or place.
The humidity sensor comes with a standardized output signal of 0-10V or 4-20mA.
The air quality is very important for our health, energy, and well-being. The CO2 and air quality digital sensors enable the transfer of measured values via 0-10V or 4-20mA output signal. They usually allow to set up the different measuring ranges and it can also be supplied with additional temperature and humidity measurement.
The air quality sensor as well as the CO2 sensor has to be placed very precisely. The CO2, for instance, is heavier than the O2, and therefore the value is higher on the floor than on the top. We suggest you install it to the height of around 1,4m on a wall without the impact of the direct airflow (windows, doors, A/C units,…).
They are becoming extremely important in many industries as well as private buildings as they can provide additional security of buildings as well as identifying the presence of people. With this knowledge, we can control many functions in automation that allow energy-savings when the place is not occupied.
The pressure can be measure in the air as well as in a liquid. It’s the basic component, especially in industrial buildings. The different measuring ranges can usually be set by DIP switch and it can also be adjusted for a particular use using a potentiometer.
The liquid pressure sensor has also different threads like for example G1/2, G1/4,… This information is very important before ordering a sensor because otherwise, it won’t fit.
As you already guessed correctly, the output signal can be 0-10V or 4-20mA.
Similar to the pressure sensor the flow sensor can also measure the airflow or the flow of liquid media in the pipes. The flow sensor for liquid media is mainly used for water shortage protection in HVAC systems. The airflow stream sensor usually controls non-aggressive gaseous flows in the range of 0,5 to 10/30 m/s.
All of them are available with 0-10V or 4-20mA output signals.
Weather is a very important part of our lives. Wind speed, wind direction, compact weather station, Stevenson screen, etc. are just some of the most popular values that can be measured. Building automation very often requires meteorological data based on its location. With correct implementation, they can prevent the damage to the building as they are made to sense the smallest local weather changes.
The output signal is 0-10V or 4-20mA.
2. Advanced protocols for sensors
In the basic list above we mostly mention the output signal 0-10V or 4-20mA. Besides those two output signals, there are of course several advanced protocols that can be used to sending the measurements over to the final destination.
Industrial protocols are different from what people use in their smart homes. Industrial building automation has to have controllers, input-output units, and sensors. The systems are usually very complex and advanced. They are always custom made. The comprehensive solution can automatically control the different offices, productions, machines, windows, doors, cooling systems, heating systems,… The most standard industrial protocols are Modbus, KNX, and BACnet.
Andivi manufacture different Modbus sensor types which are mainly implemented into custom building management systems to communicate with controller the same way as other products do. Perfectly set ecosystem is always the best way to build the systems that work for people.
Smart home protocols
Zigbee, Z-Wave, HomeKit, and Wi-Fi are just some of the most common smart home protocols. They are used to connect the devices to a hub or a gateway which allows an end-user to control those devices remotely. Are they safe? We can not answer that question as we manufacture industrial products only. But we do know that they are easy to install and use but their reliability or measuring accuracy has to be checked before the purchase.
Please do not hesitate to contact us.