So you’ve been working on a project which requires temperature/humidity data, and Google.com returned you dozens of different models. If choosing the right temperature/humidity sensor baffles you, we hope this review on 11 different temperature/humidity sensors would help you out a bit.
Products & Quick Comments
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Waterproof DS18B20 Digital Temperature Sensor
Waterproof, long range, affordable
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TMP100 Temperature Sensor (Gadgeteer Compatible) Mid price range, high performance, versatile, IIC digital output |
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Sparkfun Evaluation Board for MLX90614 IR Thermometer Expensive, long range, smooth curve |
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DHT22 Temperature and Humidity Sensor Mid-price range, Long range, nice cost performance |
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Steam Sensor Low cost, easy to use water detector |
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Soil Moisture Sensor (Arduino Compatible) For plant uses, oxidation-proof |
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Infrared Thermometer Module Cost-efficient, high sensitivity, long range, easy to be embedded, non-contact |
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SHT1x Humidity and Temperature Sensor High-end heavy duty sensor, quick response, high reliability and stability, auto sleep, low power consumption |
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DHT11 Temperature and Humidity Sensor Cost-efficient, for less demanding jobs |
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LM35 Analog Linear Temperature Sensor Cost-efficient, analog linear sensor |
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18B20 Temerature Sensor (Arduino Compatible) good cost-performance?digital sensor |
Part I. Basic Specs This part mainly deals with basic specs such as the interface, size, working voltage, soldering and price, to help you with preliminary screening with physical space, interface and budget.
Product |
Size |
Price |
Interface |
Voltage |
Need Soldering? |
TMP100 Temperature Sensor (Gadgeteer Compatible) |
32 x 27mm |
$11.50 |
IIC(Analog4,5?/IDC10 |
2.7V~5V |
Y |
Sparkfun Evaluation Board for MLX90614 IR Thermometer |
31 x 23mm |
$49.95 |
IIC(Analog4,5? |
3V/5V |
Y |
DHT22 Temperature and Humidity Sensor |
38 x 20mm |
$9.50 |
1 analog (can also be digital via converter cable) |
+5V |
N |
SHT1x Humidity and Temperature Sensor |
32 x 27mm |
$21.00 |
2 digital |
3.3V-5.0V |
N |
Infrared Thermometer |
12x13.7x35mm |
$49.00 |
3 digital |
3V/5V |
Y |
DHT11 Temperature and Humidity Sensor |
22 x 32mm |
$5.20 |
1 digital |
3.3V-5.0V |
N |
LM35 Analog Linear Temperature Sensor |
22 x 30mm |
$4.50 |
1 analog(can also be digital via converter) |
+5V |
N |
18B20 Temerature Sensor (Arduino Compatible) |
22 x 30mm |
$4.00 |
1 digital (1-Wire) |
3.3V/5.0V |
N |
Part II. Range & Precision If you insist toasting the sensor on fire, it might not taste as good as kebab…So please stay within the temperature scope when using the sensor. The first thing you need to do is to determine the measurement range, then the precision. Precision refers to the value at a certain temperature. It varies with different segments, so please remember checking the datasheet as well. If a constant temperature is hardly achievable in some situations, high measurement precision is not appropriate, because it will change with humidity/temperature drift.
Sensor |
Error |
Resolution Option |
Range |
TMP100 Temperature Sensor (Gadgeteer Compatible) |
±2°C @-25°C ~85°C±3°C @-55°C ~125°C |
Y |
-55°C to 125°C |
Sparkfun Evaluation Board for MLX90614 IR Thermometer |
±0.5°C |
N (0.02°C) |
-55°C to 125°C?Working? -70°C to 380°C?Measurement? |
DHT22 |
Temp±0.5°C /Humid±2%RH |
N (Temp 0.1°C /Humid 0.1%RH? |
Temp -40°C-80°C /Humid 0-100%RH |
Infrared Thermometer Module |
±0.6? |
Y (Max1/16?) |
-10~50??Working? -33~220??Measurement? |
SHT1x Humidity and Temperature Sensor |
Temp±0.5°C/Humid±4.5%RH |
N |
Temp 0-50?/Humid 20-90%RH |
DHT11 Temperature and Humidity Sensor |
Temp±2°C/Humid±5%RH |
N |
Temp 0-50?/Humid 20-90%RH |
LM35 Analog Linear Temperature Sensor |
±0.75? |
N |
-55 to 150°C |
18B20 Temerature Sensor (Arduino Compatible) |
±0.5°C |
N(0.5?? A/D Precision Switch |
-55 to 125°C |
Part III. Response Time This part compares the response time between the MCU sends a request and receives from different sensors. The network used is RTT. This value varies greatly with the program (such as delays) and means of communication. The fastest response comes from LM35, which has an output voltage proportional to the temperature. Bus communication is related to the communication protocol, while 1 - Wire communication takes longer time than IIC. Also because of the single bus shared by multiple modules, and can only be time-division multiplexing, may result in large time delay. As a result, it is not recommended to connect multiple devices on the same single bus.
Part IV. Performance (Temperature tracking ability) The way I used is really simple and may not be so scientific: place outdoor then retrieve back (It’s winter), to observe how long it takes for the temperature to achieve stable result after dramatic change. First let’s take a look at two IR temperature sensors, and get a rough idea of the high precision. Whatsmore, since they work without contacting the object, they can be very useful in measuring moving objects, small objects/low specific heat objects, drastic temperature change on object surfaces and

In a word, these two IR temperature sensors react sensitively to temperature change, and adapt quickly to environmental temperature. Compared with the Infrared Thermometer Module, the MLX90614 IR Thermometer has a smoother curve with less jitter.
MLX90614 IR Thermometer Rating??????
Pros: Smooth curve, long range. Has eco mode, non-contact. IIC interface. Quick response. Multiple sensors via single bus. Cons: Costy. Soldering needed. Not very easy to use (IIC Protocol doesn’t support the Arduino Wire Library). Applications: Medical instruments, office equipment (printers, scanners, etc), long range data transmission (over 20m).
Infrared Thermometer Module Rating??????
Pros?Cheaper. Smaller size (found it really suitable for thermometer pen). Nice curve with high precision and compensator. Resolution options. No library needed. Digital output. Low signal loss. Cons?Soldering headers needed. Inadequate measurement range. Need 3 digital interfaces. Applications?Same as above. Now it’s time to compare three temperature &
humidity sensors at same time.
It seems that SHT1x is the most sensitive one and achieves stable output quickly. DHT11...However, suffers from error in humidity. DHT22 is a capacitive moisture temperature measuring sensor which uses NTC thermistor.
DHT11 Rating??????
Pros?No soldering needed. Cheapest among three. Get stable output quickly. Transmission over 20m. Strong interference. Cons?Library! No resolution option. Errors: Temp+/-2°C; Humid+/-5%RH. Inadequate measuring range(0-50°C). Applications?Gardening, Agriculture.
DHT22 Rating??????
Pros?No soldering needed. Adding a few bucks to DHT11 and get an upgrade. Smooth curve. Smallest error. Large range. Transmission over 20m. Strong interference. Cons?Can be more sensitive. Slow temperature tracking. Library needed. Applications?Environmental Monitoring.
SHT1x Rating??????
Pros?No soldering. Smooth curve. Small error. Quick response. Low power consumption. Auto sleep. Extraordinary long term stability and consistency. Cons?Two digital interfaces. Humidity error. Same measuring range with DHT11. Library needed. Applications?Heavy duties and longtime installations. Following are three relatively cheap choices.

LM35 Analog Linear Temperature Sensor Rating??????
Pros?Super user-friendly – one analog cable is enough! Fast response time. Large temperature measurement range. Cheap. Cons?No resolution option. Low precision. Errors… Application?General occasions that do not require high precision. I also gathered temperature sensors that I think to be high performance: DS18B20, TMP100, SHT1x and DHT22.
TMP100 Temperature Sensor Rating??????
Pros?Resolution options from 9~12bit. IIC Protocol. Maximum 8 sensors on bus. Supports IDC10 interface. Short stabling time. Cons?Soldering needed. Jumper cable manual setup. Don’t forget to change address in program. Library needed. Application?Power supply system monitoring, Computer overheating, Thermo control system.
18B20 Temerature Sensor Rating??????
Pros?All-around player. Cheap. Resolution options (9-12bit). No soldering needed. Easy connection. Long measurement range. Cons?Library needed. Changing resolution not mentioned in sample code. Single bus. Takes a while to stabilize. Application?Wide. Home appliances, automotive electronics, instrumentation, medical equipment, industrial productions.
Epilogue Still got no idea of which one to use for your project after reading? That’s the exact feeling I got as well. Anyway, hope it might aid just even a tiny little bit, and keep making.