Thermocouple Sensors – Several Factors You Ought To Take Into Consideration When Choosing a Temperature Sensor Thermocouple.

Do you wish to find the correct sensor for the DIY project based on the Arduino microcontroller? Well, choosing the best sensor requires research and also to facilitate this process, you’ll find all of the info you want on this page. But when there’s one important thing better in the DIY culture than theory it’s practice.


Temperature sensors are popular to sense the temperature in an environment. All of them function in the similar way, but have slightly different features. According to these traits, I’ll take you step-by-step through the most effective practice of deciding on the best temperature sensor for the project with the Arduino microcontroller.

If you are already a champion of measuring the temperature and merely want a little bit more information, or you are looking at digging deep in to the Arduino temperature monitoring space, these 11 temperature sensors should cover all kinds of temperature sensors found in robotics and automation.

Temperature sensors comparison of numbers: DS18B20, LM35DZ, DHT11, thermocouple temperature sensor, MLX90614, LM75, SHT15, TMP100, RHT03, TPA81, D6T MEMS

Temperature sensors comparison of numbers: DS18B20, LM35DZ, DHT11, Thermocouple Type-K, MLX90614, LM75, SHT15, TMP100, RHT03, TPA81, D6T MEMS


Mainly because it matters which kind of project you’re looking for, I hope to have something listed that can help you:

fire fighting robot able to ascertain the way to obtain fire and do something;

a mobile robot in a position to detect to observe the temperature and send data via Bluetooth or Wi-Fi to a server and view the temperature particulars on a smartphone or a tablet;

a wireless sensor network at home to adopt decisions and controls the heating and air cooling unit;

a security alarm system that senses the actual existence of a human;

Temperature sensors for hobbyists

The temperature sensors for hobbyists are cheap in comparison to the sensors on average, nonetheless they serve the identical purpose – reading the temperature. Well, none of these sensors can consume the sun, but are ideal for homemade robotics and automation applications since they are very easy to interface, accurate, and contains a quick response time. When you place your finger into it, immediately the output of the sensor actually starts to rise.

With this part of the article, I’ll examine deeply the features, price, how you can interface the sensor and the best applications for every sensor.

1. DS18B20

The DS18B20 can be a cheap digital temperature sensor with a value of only $3.95. The sensor can be used in a multitude of hobbyist applications for both beginner as well as others which can be more skillful.

This sensor has 1-wire interface, which means require just one single pin to convey together with the microcontroller. More than that, it can be designed with an exclusive serial number that permits you to interface more sensors about the same data bus.

The accuracy of the measurements is high since the sensor is not going to rely on the accuracy in the microcontroller to look at the analog signal. And because this sensor has a digital output, you simply will not get any signal degradation even over long distances.

The sensor is commonly used in quite a number of applications including temperature sensing and monitoring robot, air temperature monitors, etc.

Note: The DS18B20 has a waterproof version created to measure the temperature in wet condition. This sensor is jacketed with PVC, and all you know about interface and specifications remains to be the same.

This tutorial helps guide you to wire the sensor with an Arduino UNO board and study temperatures detected with the sensor. From the sketch is named the DallasTemperture library that helps you to utilize this sensor super easy: Arduino – One Wire Digital Temperature Sensor – DS18B20.

2. LM35DZ

Sometimes I don’t assume that we could buy sensors at a cost less than a coffee. The LM35DZ is probably the cheapest temperature sensor in the DIY community. It features a price of only $1.57.

The sensor is calibrated directly in Celsius degrees, and also the only functional mode is definitely the analog output directly proportional to temperature.

This is the ideal sensor for Arduino projects because it can be powered directly with 5V in the Arduino’s power pin and has only three pins (one pin is for analog output as well as two for power source).

Having a sealed circuit, the sensor cannot be exposed to oxidation and is often used to appraise the temperature of water accurately. On the whole, the sensor can be used for simple projects to showcase upon an LCD the actual temperature to advanced robots in a position to detect the fire within a room, warehouse or perhaps a forest.

In this tutorial, you see the scheme of your circuit with the circuit connection and the Arduino sketch to showcase the temperature detected with the sensor in Celsius and Fahrenheit degrees. To discover more the LM35DZ features, the Instructables user HarshV helps guide you to create an automated cooling system.

3. TMP100

The TMP100 has three features that make it one of the best temperature sensors for DIY projects. The initial feature would be that the sensor supports an input voltage of 2.7V to 5.5V, that is against the TMP102 sensor that needed an input voltage between 1.4V and 3.6V. The next feature is the two address pins that allow you to control as much as eight sensors on one I2C bus. The next important feature is its waterproof property that made it good to read through the temperature in damp or dry location. Also, the sensor could be attached to a horizontal deck or upside-down.

If it leaves the Texas Instruments factory, the sensor can be a tiny and compact chip that appears such as a spider with six legs. To work more quickly using the TMP100 sensor, You should to utilize a breakout board. The DFRobot small breakout board having a built in TMP100 sensor is an excellent option at a price of $11.55.

A similar web shop shows you in a tutorial how to interface the TMP100 breakout board having an Arduino clone and study the temperature detected.

4. DHT11

At a price of $5.33, the DHT11 has cost/performance advantages and is also a fairly cheap sensor to study the temperature and humidity. It’s a sensor with an superior quality but with a genuine downside since look for digital signal once every 2 seconds.

Otherwise, it’s quite simple to embed the sensor within your project as well as monitor the nearby air.

The DHT sensor has two versions: DHT11 and DHT22. Both sensors are really good to appraise the temperature and humidity, although the characteristics are not the same.

When compared with DHT11, the DHT22 is good to appraise the temperature from -40 to 125°C and it has a better accuracy than DHT11. But even it cannot read a large range of temperature, the DHT11 is smaller and less expensive than DTH22.

In this particular tutorial, you find information how you can wire the sensor, install the DHT11 library and display on Arduino’s Serial Monitor the values generated with the sensor.

From reading to displaying the temperature with an LCD screen is a matter of minutes. If you wish to try something aside from a straightforward reading temperature application, you can try a system to check the temperature and humidity of a room and display the values recorded with an Liquid crystal display plus a website.

5. RHT03 (DHT22)

RHT03 (also known as SHT22) is actually a digital temperature and humidity sensor which comes calibrated and doesn’t require additional components to monitor the environment inside a room or warehouse. The sensor is simple to use with any Arduino microcontroller and possesses a value of $9.95.

Compared to its little brother DHT11, the DHT22 is more accurate and may read the temperature and humidity more than once every second or two.

This tutorial explains every detail to interface and display humidity and temperature recorded through the sensor.

6. LM75

LM75 is an additional very cheap digital sensor by using a cost of only $2.21. This sensor has two important features: it can be inexpensive and designed as an I2C temperature chip.

The sensor is really a surface mount device, and you need to solder wires onto it. It is a good sensor for hobbyists and students to learn to monitor the temperature.

With this guide, you find an Arduino sketch to show the temperature recorded with the sensor.

Temperature sensors for automation & process control

Temperature sensors for automation and process control can be very expensive when compared with hobbyists and temperature sensors on average, and are usually accustomed to monitor the temperature in environments with great fluctuations or precise data logging.

In this portion of the article, I’ll examine deeply the characteristics, applications and the way to use each temperature sensor (SHT15, Thermocouple Type-K) for automation and process control with all the Arduino microcontroller.

Temperature sensors for automation & process control (SHT15, Thermocouple Type-K)

Temperature sensors for automation & process control (SHT15, Thermocouple Type-K)

7. SHT15

SHT15 is really a precise humidity and temperature sensor created to function in environments with greater fluctuation in humidity and temperature. At a price of $41.95 on Robotshop, the sensor comes fully calibrated with 2-wire digital interface.

In this tutorial, become familiar with the way to get the temperature and humidity recorded by the sensor.

8. Thermocouple Type-K

The majority of the temperature sensors using this article cannot reach higher temperatures than 125 C degrees. The Thermocouple Type-K is different and works on higher operating temperature than most sensors.

Considering its features, it can be likely to are more expensive than some other sensor. The fact is that the thermocouple is an easy mixture of two sensitive metals and contains a value of just $9.95.

It possesses a simple digital 2-wire interface and measure not more than 1 meter (around 3 feet). The sensor requires an amplifier like MAX31855 that output an electronic digital signal on the Arduino microcontroller.

As well as an Arduino board, the Type-K sensor can be used to look at the temperature in heaters and boilers, HVAC systems, etc.

The Adafruit tutorial demonstrates how to wire the Thermocouple together with the MAX31855 amplifier and display the temperature detected by the sensor.

Temperature sensors for projects with special needs

DS18B20, TMP100, or DHT11 are usually a great choice if you wish to monitor the temperature in a room or outside within a forest thus making you content with any project. But what if you want to detect the movement or the quantity of persons in a room? With this category enters three of the special temperature sensors.

Every one of the sensors contained in this part of the article are utilized in special projects because works different and study the temperature distinctive from what we know already about classic temperature sensors.

Temperature sensors for projects with special needs (MLX90614ESF, TPA81, D6T MEMS)

Temperature sensors for projects with special needs (MLX90614ESF, TPA81, D6T MEMS)

9. MLX90614ESF

The MLX90614ESF sensor senses the temperature by sending infrared light to remote objects. Since the sensor sends infrared waves, it might sense the temperature of the object without touching them physically.

Using a expense of $19.95, the sensor is easy to use, has good accuracy and high resolution.

The sensor is ideal for a wide array of applications and particularly when is required to measure the temperature spanning a 90-degree field of view.

Communication with the MLX90614 is achieved through two strategies for output: PWM and SMBus.

This is an example demonstrating the usage of MLX90614ESF sensor. It makes a fundamental application that lets you observe the infrared sensors at your workplace.

10. TPA81

The infrared sensor with built-in lens, paired with increasingly sophisticated module to study the temperature of eight adjacent points simultaneously, may be capable of some very interesting things.

It is possible to set it up to detect the warmth of the body system or perhaps a candle flame at a variety of 2 meters (around 6 feet).

The sensor includes a value of $105.44 and communicates by using a development system from the I2C interface.

This tutorial covers the software and hardware setup expected to connect the TPA81 sensor by using a microcontroller. The sensor makes possible the temperature detection in dexopky90 large variety of applications including the NAO humanoid robot that utilizes the TPA81 thermal sensor to detect the high temperature source.

11. D6T MEMS

Maybe you want something to take place when nobody’s home or maybe you head into a room, enjoy having the lights switched off or on. Operating about the infrared waves, you can see the DT6 sensor since the logical next phase for monitoring an area, security or safety monitoring.

This little smarter sensor can count the volume of people in an area, even when not one of them moves.

The sensor carries a value of $49.88 and communicates together with the Arduino microcontroller by using an I2C interface.

This PDF file will show you getting the measurement values from the infrared sensor.

Failure mode

Not all temperature sensors are the same and in some cases they could read high or low temperatures. When you don’t actually know if it’s a sensor failure, you need to check below the most prevalent failure mode of a temperature sensor.

1. Sensor heated by the electronics

This might be just about the most common errors when you use a sensor to keep track of or detect the temperature. When the sensor is heated by the electronics, the sensor is not going to report the appropriate temperature. Initial step is to localize the heating or move the sensor beyond the enclosure.

2. Library error

When you use the Arduino to appraise the temperature through the sensor, in the Arduino sketch is called a library suitable for the sensor. You should be certain that the library from your sketch is one that secure the sensor type.

3. Temperature exceeds the max temperature

This is amongst the worst scenarios for any system that study the temperature. Usually, the company writes from the datasheet of the sensor what will happen in case the temperature exceeds the highest temperature maintained by the sensor. Inside the worst case, whenever your sensor reached the most temperature, your chip might take an inside damage or might melt.

Tips: Always is nice to decide on a sensor that could support every one of the temperatures assumed to get measured. All the sensors explored in this post usually tend to be more accurate once the temperature reaches the values from the midst of the product range.

4. Correct conversion between Celsius and Fahrenheit

You must make your right conversion between Celsius to Fahrenheit or Fahrenheit to Celsius. In the datasheet from your manufacturer, you find the sensor information regarding measurements.

5. Heat conducted down the wire

When your sensor is in touch with a wire, the wire can conduct an unexpected amount of heat. The contact in between the wire and sensor is surely an issue, particularly when you monitor the temperature along pipes.

6. Condensation in the morning

Condensation in the morning can destroy any project or perhaps your expectations regarding the temperature measurements. The condensation appears in each and every morning when warm moist air meets the cooler dry air. In this case, the liquid vapors can condense on electronics in the same manner it can do on grass. Therefore, if you feel any project is exposed to condensation, you will need to use materials that keep water vapor condensation from as a problem.