Selecting the Best Temperature Sensor

How to Select the Optimal Temperature Sensor?

AM2301/DHT22 temperature sensor

Selecting a good temperature sensor can be hard. Although there are many options we are going to discuss which are best for your situation. Ultimately this question depends on what the temperature sensor will be used for and where it will be located. Will the Sensor be in a damp environment? will the sensor need to be waterproof? Do you also need to measure humidity? etc. The list can go on forever.

 

 

dht11 temperature sensor

 

 

The first sensor on our list is the DHT11. The DHT11 is a cheap and reliable temperature sensor for a hobbyist who is looking for casual temperature monitoring. The DHT11 Temperature/Humidity sensor is not waterproof and should not be used for anything that requires extremely accurate temperature logs. However, this sensor is perfect for small projects that are utilizing basic microcontrollers since there is a myriad of open source libraries to interface with the DHT11. Specs:

  • Operating Voltage: 3.5V to 5.5V.
  • Operating current: 0.3mA (measuring) 60uA (standby)
  • Output: Serial data.
  • Temperature Range: 0°C to 50°C.
  • Humidity Range: 20% to 90%
  • Resolution: Temperature and Humidity both are 16-bit.
  • Accuracy: ±1°C and ±1%

 

 

am2315 temperature sensor

 

 

The second sensor on our list is the AM2315. This sensor is water-resistant and comes with a nice mount to be used in commercial applications. The AM2315 uses the I2C Protocol and is a bit trickier to interface with. However, this sensor has superior specs to the DHT11. The only downside to the AM2315 is the range that it can measure. If you are looking to put the AM2315 in an environment that experiences temperatures below 0F it will not work. Specs:

  • 3.5 to 5.5V power and I/O.
  • 10 mA max current use during conversion (while requesting data)
  • Good for 0-100% humidity readings with 2% accuracy.
  • Good for -20 to 80°C temperature readings ±0.1°C typical accuracy.
  • 0.5 Hz update rate.

 

 

dht22 temperature sensor

 

The last sensor that you should consider is the DHT22. This sensor uses a one-wire data connection and has a lot of libraries (like the DHT11) that make it extremely easy to interface with. This sensor is only a couple of dollars more expensive than the DHT11 but the accuracy and temperature range that you can measure with this sensor is far superior. If you need a relatively low cost and highly accurate temperature sensor? I would highly recommend giving the DHT22 or any of its predecessors a try (AM2302 if you need an enclosed version of the DHT22). Specs:

  • Operating Voltage: 3.5V to 5.5V.
  • Operating current: 0.3mA (measuring) 60uA (standby)
  • Output: Serial data.
  • Temperature Range: -40°C to 80°C.
  • Humidity Range: 0% to 100%
  • Resolution: Temperature and Humidity both are 16-bit.
  • Accuracy: ±0.5°C and ±1%

In conclusion, if you are doing a hobby and or a small school project and need a cheap and relatively solid temperature sensor? Go with the DHT11. Do you need an enclosed sensor that can handle some rough weather and are not worried about paying a bit more? Go with the AM2315. Need a highly accurate temperature sensor that works well in freezing and extremely hot weather? Go with the DHT22.

Feras | June 28, 2019, 2:34 a.m.