With Sensirion humidity and temperature sensors you can be sure of what you measure. Moreover, now we´ll support your development by free samples.
Top-class calibrated humidity and temperature sensors Sensirion already gained many fans. Mainly thanks to a fact, that they´re not only “sensors” but a ready-made solution with a pre-amplifier, ADC and other circuits, which directly provide a final value in a digital form. That´s why it´s not necessary to solve input portion (noise, shielding, power supply, length of wires,…). Moreover, their long-term stability is verified in a praxis.
Features and usage of Sensirion sensors was introduced to you in many our articles. In the Sensirion portfolio can be found easily solderable types on a small PCB like for example SHT11(15) or SHT71 (75), as well as miniature types in SMT DFN packages like for example SHT21 (25) and also the new SHTC1. Small DFN package is practically impossible to solder manually, but it´s relatively easily manageable by means of a solder paste and a hot-air soldering station or ideally by a reflow in a hot-air oven.
Maybe, you´ve already noticed, that in many articles we also bring you a contest with a possibility to win free samples of a given component. We usually draw by lots 1-10 winners, which will directly receive free samples.
Still, if you´re seriously interested to try a given sample for a development of your (industrial) application, please contact us by e-mail. In many cases, we can provide you a given sample even if you wasn´t one of lucky winners of the contest.
Evaluate the Swiss precision for free! – [Link]
Complete digital temperature sensor Sensirion STS21 provides a top-level accuracy and stability for a very affordable price.
Digital sensor STS21 s the newest member of calibrated humidity and temperature sensors family SHT2x (SHT21, SHT25). In opposite to them, STS21 is able to measure only temperature, i.e. it´s suitable only for applications, where we don´t need to measure humidity. However a smaller functionality has also a significant positive aspect in a form of a substantially lower price. STS21 contains on a chip, similarly like its familiar, a temperature sensor, precise supply, low noise linear amplifier, AD converter and a serial interface with I2C output (fixed address different from SHT series).
Basic accuracy of STS21 in the 0 to +60°C temperature range is +-0.2°C. The user can choose a resolution for measuring and it can be 11-14 bits (up to 0,01°C). Despite the fact, that the sensor hasn´t guaranteed absolute accuracy of 0.01°C, such a high resolution can be beneficial for example for monitoring of a tendency (increasing/ decreasing) of temperature.
Detailed information can be found in the Sensirion STS21 datasheet.
STS21 measures temperature with an 0.01 °C resolution – [Link]
Humidity can be measured by various sensors, but sensors SHT from company Sensirion add many benefits moreover.
To be exact, a word „sensors“ is not a suitable expression in this case. As SHT series sensors contain on one chip humidity and temperature sensor, precise supply, low noise linear amplifier, AD converter and a serial interface, they represent a ready-made “device”. Moreover, they´re calibrated, thus to get an exact value it´s only necessary to read out data through a serial interface. In case of SHT2x series, it´s a standard, easy-to-implement I2C interface.
Sensirion sensors SHT2x series was more in detail introduced to you in our article „New sensors Sensirion will take you only 3x3mm on PCB!”, that´s why we´d like to bring you mainly few tips for simplification of development now.
Area of relative humidity and physics of water vapors is quite ample and into its introduction will initiate you the document Introduction_to_Relative_Humidity. Don´t be scared of many quotations, which you´ll find there – fortunately in common praxis we usually manage it with values of relative humidity and a dew point, which can be found together with code examples in Humidity_at_a_Glance.
As humidity sensors are very often used in residential places for regulation of heating and ventilation, also useful can be information about influence of humidity on a thermal comfort. For a practical usage of sensors it´s also important their placement on a PCB and a good access of air, what is in detail described in the document Sensirion_Humidity_Design_Guide. SHT2x are intended for 3VDC power supply, that´s why when using in 5V applications, you can face a problem of different voltage levels. This can be easily solved for example by a circuit described in the document SHT2x_5V_Supply_Embedding.
The program itself doesn´t need to be developed “from zero”. Examples can be found in the document SHT21_Sample_Code and SHT2x_Electronic_Identification_Code. Detailed information about testing and specification of SHT sensors can also be found in documents Sensirion_Humidity_Sensor_Specification_Statement and Sensirion_Humidity_Testing_Guide.
SHT25 – humidity and temperature precisely in every season – [Link]
Calibrated humidity and temperature sensors Sensirion SHT21, SHT25 and STS21 excel by very small dimensions. Thanks to their miniature size and a very low power consumption, you can use them even in small portable devices.
Sensors SHT21, SHT25 and STS21 with I2C digital output belong to the SHT product line, with the CMOSens technology of swiss company Sensirion. SHT21 and SHT25 measure relative humdity and temperature, STS21 measure only temperature. With a new CMOSens chip, reworked capacitive type humidity sensor and the improved band-gap temperature sensor they feature excellent properties. They have very similar and in some aspects even better properties than SHT1x and SHT7x sensors. Also these sensors belong to high quality CMOS sensors, which contain all elements of the measuring chain on one chip: humidity and temperature sensor, precise supply, low noise linear amplifier, AD converter and interface. Inspite of very compact dimensions also SHT21 and 25 sensors remain resolution of 12 bits for relative humidity and 14 bits for temperature. Temperature sensor STS21 has also a 14 bit resolution and a user can choose by a command the resolution of 14, 13, 12 or 11 bits.
I2C interface enables a very simple communication with a host microcontroller, in a Hold/ No Hold Master mode. Defaultly sensors have the same I2C adress set from production. Upon request it is possible to provide sensors with various adresses from producer. STS21 is fully compatible with SHT2x but it has a different I2C address. This enables to use sensor STS21 in applications where humidity measurment is optional and enables to use the same hardware.
New sensors Sensirion will take you only 3x3mm on PCB! – [Link]