LPS22 pressure not accurate or damaged?

[BDELR.1]

Hello,

I have made a custom board with lps22hb. I am trying to get accurate pressure but it fluctuates with time. As I plotted a graph showing pressure and temperature I figure there is a direct relationship. I think that according to the datasheet, it should be accurate at +/-0.1hPa between 0-65°C. So is my sensor damaged? or there is a temperature compensation to make?

During the test, the board was on my desk measured at 28°C and then on a table outside measured at 20°C. Pressure scale on the left, Temperature scale on the right and Time in hours.

Regards,

Bertrand.

[TBomb.1]

Hi Bertrand, do you have a reference pressure sensor to check the actual pressure?

And do you have soldered the part by hand or you used a board from ST? It might suffer from marginal damage if the soldering process has had some criticalities.

It would be good if you could test another device and check whether it behaves the same way.

Tom

[BDELR.1]

It has been soldered by hand on a custom PCB and a stencil. The soldering process was done with reflow oven. Reading the datasheet I see how critical is this process. I have a STEVAL-STRKT01 with the same component. I will manage to make a test and let you know.LPS22 is component U10 on the board.

[BDELR.1]

With steval-strkt01 with LPS22 I have better results. Looking at nearby airport Metar the pressure increase from QNH=1017 to 1019 during the test (40m AMSL):

made an other test simultaneously with 2 ms5611 (without temp):

All sensors showed a good accuracy knowing the envirenmental pressure increased by around 2hPa.

So I think the barometer on my custom board is dead??

[BDELR.1]

The sudden decreasing temperature with steval-strkt01 is me opening the box because it was slightly warmer than my desk because of battery charging. The pressure is not following the temperature like in first graph.