Strange properties of the sensor gel BMP384.

[IgSel]

Hello! I want to use your interesting (waterproof) BMP384 sensor. I have been trying two sensors for a long time in the mode of static accumulation of pressure and temperature measurement results and found this. After prolonged (several hours of operation) in water and subsequent drying of the sensor in the air, its readings when re-immersed in water at first (about an hour) show values 2-4 mmHg lower than the height of the water column in cm. Then gradually the readings are aligned and the sensor shows the correct result. Is this a property of the gel?

Thanks!

[BSTRobin]

Hi IgSel ,

Could we know some information from you:
Did you do calibration before you used BMP384?
How long does it dry?
Are the test results the same for both sensors?

[IgSel]

Yes, of course. Temperature and pressure calibration using calibration constants from registers 0x31...0x45. The two sensors showed the same results with an accuracy of about 100 Pa. They were periodically taken out of the water for several hours (until completely dry) and then again immersed in water for several hours. Thank you for paying attention to my question. Answer then what is stored in register 0x30 (is this the same information as in BMP388?). If this is the case, then why can't I get a self-test with BMP384 (using the CRC8 counting algorithm for BMP388)?

[BSTRobin · Accepted solution]

Hi IgSel ,

If you are using BMP384 measuring water depth. BMP384 is a waterproof barometer but not being used to work underneath water. Therefore, we can't ensure its performance when working to measure water depth.
BMP384 trimming values(0x31~0x45) were different with BMP388.
Currently BMP384 hasn't support self-test. We consider to support self-test in the future.