They are temperature-sensitive resistors. Their functionality is based on the change in internal resistance as the outside temperature rises or falls, as does the voltage internally. Obviously this is completely analog technology.
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PageImage: 73 - EDITresistencia térmica tipo ntc o ptcPageImage: 73 - EDITPageImage: 74 - EDITthermal resistance type ntc or ptcPageImage: 74 - EDIT
This is the type of sensor or thermal probe used in current consumer electronics. It is easy to find in the electronic components market.
They do not require a special thermostat and can be tested with an electronic multimeter.
Disadvantages of analogue NTC or PTC probes
The reading is not very precise.
The quality and length of the cable can vary the sensor reading.
The passage of natural time can vary the accuracy of the sensor.
The thermostats that use these probes can be configured in order to fine-tune their accuracy, but it will not be easy if the probe is already installed in a difficult-to-access location.
If several comparative probes are used, as is the case with a solar heater, the difference in precision can make our lives relatively complicated.
They are not resistors like the previous ones. It has a very similar appearance to a transistor. They are pure digital devices as if they were micro computers. The device that manages it literally asks what its temperature is, and this digital probe answers with the exact data.
They are widely used in recreation and learning about domestic electronic uses and home automation applications. The most popular among digital probes is the DALLAS B18B20.
It is very popular in the world of Arduino.
PageImage: 75 - EDITa Dallas DS18B20 digital probe with an arduinoPageImage: 75 - EDIT
The Dallas Ds18b20 digital probe looks like this:
PageImage: 76 - EDITDallas DS18B20 Digital Thermal ProbePageImage: 76 - EDITPageImage: 77 - EDITDallas DS18B20 Digital Thermal Probe with HolsterPageImage: 77 - EDIT
These little devices are made up of 3 legs. Two of them are for supplying voltage (5v). The 3rd leg is the one used for digital communication with your thermostat or any similar device that manages it.
Here is the identification of the legs of the ds18b20 sensor:
PageImage: 78 - EDITIdentification of legs in Dallas DS18B20 digital thermal probePageImage: 78 - EDIT
Nowadays they are easy to find in the digital market, usually in stores such as Aliexpress, Amazon, Ebay, etc.
Poor quality, aging or excessive length of its wiring will not affect its reading accuracy at all.
Thermosters do not need to calibrate or fine-tune the readings of these probes, because they are real and really accurate data.
Generally, their minimum and maximum temperature range is wider than analog probes.
Many probes can be placed in parallel on the same cable, since internally they function as a telecommunications network. (you could even put several probes in a hard-to-reach place, so you can alternately select another one in case of a fault)
The device that manages the probes can configure their order without performing physical operations, since each probe has an internal digital address.
Disadvantages of Dallas 18B20 digital probes
They need special thermostats for the use of these digital probes.
They cannot be tested with an electronic multimeter, a compatible device is needed, or an arduino or raspberry with the code loaded for this use.
The reading is much slower than an analog probe. If you use many probes and set them to high precision, the LinkUrlLatencyLinkUrl time may be a bit high.
Documento creado por Pedro Reina Rojas 15 de March de 2021 thermoresistor, sensor ntc, sensor pt100, thermosensor, thermal probe, sensor ds18b20, sensor ptc
Más de 20 años de experiencia en programación. Programador PHP Senior BackEnd. (un poquito fullstack a veces) Programador Django. Programación por ocio con Arduino y rasperry Pico.
