Smart Cities

The first devices in a family of humidity sensors from Texas Instruments are claimed to provide the industry’s highest reliability and accuracy and the lowest power consumption. The HDC3020 and HDC3020-Q1 have built-in protection for sensing elements to create more reliable industrial and automotive systems that withstand potential damage caused by moisture, reacting as needed to changing water vapour conditions over time.

From extending the life of produce during transport and storage, to keeping automotive cameras clear of fog, to controlling air quality and flow in buildings, the need for improved reliability and safer, more comfortable environments has increased the adoption of relative humidity (RH) sensors.

The HDC3020 and HDC3020-Q1 offer improved relative humidity measurement accuracy with reduced long-term error, when compared to existing RH sensors, says TI. They preserve data integrity under stress conditions and are claimed to be the industry’s first to provide integrated correction to adapt to drift caused by natural aging, environmental stress or interactions with contaminants.

The humidity sensors achieve lower drift in extreme conditions than competing devices, with less than 0.21 per cent RH accuracy drift per year and less than five per cent RH drift from temperature and humidity stress (tested up to 85 per cent RH and 85 degrees C). This sustained accuracy enables longer system lifetimes, eliminating the need to frequently replace or recalibrate the sensor.

When exposed to stress or contaminants, the sensors also provide a second line of defence, where even a small accuracy drift from the sensor’s time-zero specification can be removed using integrated drift correction technology.

The HDC3020 and HDC3020-Q1 are verified with a procedure traceable to the National Institute of Standards and Technology for the full supply voltage of 1.62 to 5.5V and the widest temperature and humidity range at ±1.5 per cent RH. This level of accuracy enables more precise control of a system, increasing efficiency by ensuring that the system only runs when necessary.

The sensors are available in several pin-to-pin compatible package cover options, such as removable polyimide tape and permanent IP67-rated filter covers. The covers provide ingress protection against dust and moisture for the devices during assembly and system lifetimes, and help maintain accuracy when the sensor is exposed to contaminants.

Low power consumption (nA) across the supply range from 1.62 to 5.5V enables low power operation while a system is actively running and when in sleep mode. An automatic measurement mode enables humidity sensing at regular intervals to capture data while the rest of the system sleeps to preserve system battery life in applications such as cold chain data loggers, wirelessly connected environmental sensors such as air-quality monitors, smart home or wireless sensor nodes in buildings or IP network cameras.

Preproduction versions of the HDC3020 and HDC3020-Q1 in eight-pin leadless plastic small outline packages are available exclusively from the TI website.  Additional devices with analogue output and packages with protective covers are expected to be available by the end of the year.

http://www.ti.com