01-04-2022 04:21 PM
In the BMP388 data sheet (linked here for convenience) in Section 1 "Specification," there are "operational" and "full accuracy" ranges listed for temperature, but only "full accuracy" is listed for pressure. Is there a pressure operational range?
The reason for my asking is because I have recently collected data which corresponds to pressure values as low as 4882 Pa (48.82 hPa) which is much lower than the datasheet stated range of 300...1250hPa.
Are my measurements of 48.82hPa valid, and if so what is the relative accuracy I should expect? I see the data sheet states typical relative accuracy of pressure in the range of 900...1100hPa, but nothing regarding beyond that range.
I am fairly confident in these measurements (+/- 3hPa) as this was part of an aloft balloon experiment with GPS altitude measurement.
01-04-2022 04:45 PM
Hello balloon-89412,
When you got 48.82hPa pressure value, what was about the temperature at that time?
01-04-2022 04:49 PM
Hi BSTRobin,
The BMP388 reported temperature was 49degC. We do not expect this to match ambient (atmospheric) temperatures due to microcontroller heating and thermal insulation of the package.
Hope this helps.
Thanks in advance,
balloon-89412
01-04-2022 09:31 PM
Hi balloon-89412,
Thanks for your inquiry.
First of all BMP388 has been discontinued. Please see the attached PDN for more information. Please switch to BMP390, or the water-resistant version of BMP388 which is so called BMP384, or the new upcoming BMP580.
BMP388 has pressure operating range from 300hPa to 1250hPa with full accuracy. Your application with pressure of 48.82hPa is out of BMP388 operating range. So even BMP388 may not get damaged at such high altitude, its performance or accuracy is not guaranteed.
Thanks.
01-04-2022 09:39 PM
Hi FAE_CA1,
Thanks for your response and for pointing out the discontinuation of BMP388! I will certainly look into the replacements you mentioned.
Is there any minimum pressure the BMP388 will output?
I suppose what I am asking is, although maybe Bosch cannot make guarentees, is there some degree of certainty to be had about these low pressure measurements? Or am I just out of luck because I'm operating outside the spec? Even something like +/- 10hPa would be useful.
Best regards,
balloon-89412