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I am new to reading electronic datasheets.

The BMP280 (https://www.amazon.com/Adafruit-BMP280-Barometric-Pressure-Altitude/dp/B013W0RR6Y) has this datasheet:

https://cdn-shop.adafruit.com/datasheets/BST-BMP280-DS001-11.pdf

I'm trying to figure out how responsive it is, i.e., how long between a change from one pressure or temperature to another, and the time the new pressure/temperature is reflected in output from the device. (I see that "responsiveness" isn't a tag word on this stack exchange site, so maybe I'm just having a vocabulary problem?)

For my application, I'm hoping the response time is on the order of 0.1 to 0.25 seconds (or faster). Does that document give this information? If not, do you happen to have a guess?

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In this datasheet, the information you want is labelled as "Measurement Rate", and can be found on page 3: Image highlighting the location of the measurement rate information The rate this shows is the maximum rate at which you can get readings from the device. Since the BMP280 can take readings at 157 Hz, that means that it takes 1/157 seconds, or about 6.4 ms, between readings.

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  • \$\begingroup\$ Thank you, that's helpful. But actually that just means that the device will output measurements at that rate, not that it can necessarily measure accurately that quickly, right? As an extreme hypothetical, suppose internally it measured temperature by measuring the volume of a certain liquid. And suppose it took this liquid several seconds to expand to a stable size in reaction to a temperature change. So it suddenly gets warmer, but the device will take several seconds to be able to physically register that, but meanwhile it's giving out (inaccurate) readings every 6 ms for several seconds. \$\endgroup\$
    – M Katz
    Commented Apr 28, 2018 at 5:29
  • \$\begingroup\$ yes, thermal resistance slows down the accuracy, but that's unavoidable; you still get the same hi-res curve a set period later; use a PID controller to compensate. \$\endgroup\$
    – dandavis
    Commented Apr 28, 2018 at 9:43

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