Measuring Air Quality with IoT Sensor

Bosch Sensortec is making an IoT environmental sensor for measuring air quality. The BME680 can measure the indoor air quality, relative humidity, barometric pressure, and ambient air temperature. It has four sensors housed within a single LGA package measuring 3x3x0.95 mm, and both mobile and stationary IoT applications can use the package for use in smart homes, offices, buildings, elder care, sports, and fitness wearables.

The BME680 measures the indoor air quality through its internal gas sensor by detecting a wide variety of gases in the range of parts per billion. The gases it can detect include hydrogen, carbon monoxide, and volatile organic compounds. While measuring altitude and pressure, the BME680 is accurate to within ±1 m and ±12 Pa respectively. Its temperature measurement capability extends from −40°C to +85°C, and it can measure relative humidity from 0% to 100%. In addition, the BME680 can measure an offset temperature coefficient of 1.5 Pa/K.

The BME680 consumes current according to its measuring parameter. While capable of operating from a supply voltage of 1.71 V to 3.6 V, it has a data refresh rate of 1 Hz. When measuring temperature and humidity, the BME680 consumes 2.1 µA, and 3.1 µA when measuring temperature and pressure. The current consumption goes up to 3.7 µA when measuring pressure, temperature, and humidity, while the maximum consumption is between 0.09 and 12 mA when the device is measuring gas, temperature, humidity, and pressure. Therefore, although the current consumption depends on its operating mode, its average current consumption in sleep mode goes down to 0.15 µA.

As an integrated environmental sensor, Bosch Sensortec has developed the BME680 specifically suited for mobile applications and wearables. As for both applications the size and low power consumption are key requirements, Bosch Sensortec has expanded its existing family of environmental sensors by adding the BME680 to its repertoire, while integrating the temperature, humidity, pressure and gas sensors, all of which are highly linear and highly accurate.

The BME680 comes in an 8-pin metal lid LGA package measuring only 3x3x0.95 mm. Bosch Sensortec has designed the sensor for optimized consumption that depends on its specific operating mode, high EMC robustness, and long-term stability. The specialty of the gas sensor within the BME680 is it can detect a wide spectrum of gases for assessing the indoor air quality for individual well-being. For instance, the BME680 can detect VOC or volatile organic compounds from alcohol, adhesives, glues, office equipment, furnishings, cleaning supplies, paint strippers, lacquers, and paints based on formaldehyde.

Applications for the BME680 are numerous. It can be used for altitude tracking as well as calorie expenditure for sports activities. It is sensitive enough for indoor navigation as it can detect change of floors and elevation. As GPS enhancement, it can improve time-to-first-fix, slope detection, and dead reckoning. As home automation control, the user can use the BME680 as an advanced HVAC control. Scientific experiments can use it for measuring volume and airflow, while agriculturists can use it as warning against dryness or high temperature. Sports enthusiasts can use it for monitoring fitness, well-being, detecting skin moisture, change in room, and for context awareness. BME680 is suitable for use as a personalized weather station and for indoor air quality measurement.