Barometric pressure sensor is in gel package to protect against water ingress
Packaging a barometric pressure sensor into a compact package, small enough for use in wearable products and other portable products, Bosch Sensortec claims the BMP384 has market-leading accuracy.
A barometric pressure sensor in a wireless fitness tracker enables the wearable to detect changes in the user’s elevation, for example when walking up or down stairs, for calculating the number of calories that the user is burning. Until now, many barometric pressure sensors have not been resistant to liquids, making it difficult to integrate them into waterproof products.
The BMP384 provides a relative accuracy of +/- 9 Pa, an absolute accuracy of +/- 50 Pa, and a temperature co-efficient offset (TCO) of +/- 1.0 Pa/K. The power consumption of just 3.2mA at 1Hz data rate (typical) means that the sensor will not drain the batteries of portable devices, adds Bosch Sensortec.
The BMP384 is intended for wearables, home appliances and industrial applications in harsh environments because the sensor’s package design utilises a special gel to protect it against the ingression of mainly water, as well as other liquids and dust.
Dr. Stefan Finkbeiner, CEO at Bosch Sensortec, explains: “Until now, engineers have faced significant challenges when designing barometric pressure sensors into applications involving water or other contaminants, frequently seeing performance degradation over the final product’s lifetime. This new sensor makes design simpler and provides peace of mind.”
The new BMP384 barometric pressure sensor can be used in wearable devices, such as smart watches and fitness trackers, used while swimming or running. The special gel inside the package protects against common liquids such as salt water, rain, sweat and sunscreen. Its compact size of just 2.0 x 2.0 x 1mm3 makes the sensor suitable for extremely small devices.
In addition to wearables, the sensor will be practical for home appliances, for example water level detection in washing machines to ensure accurate water volume measurement to prevent flooding. The BMP384 is very durable, says Bosch Sensortec, making it ideal for dusty environments, for example, to detect clogging in vacuum cleaners.
The BMP384 is available now.
