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LPS22HΒ wrong pressure value

GPapa.6
Associate II

Hello,

these days i tested the pressure sensor lps22hb,the pressure measured is 43 hpa lower than it should,that is it show 970 hpa while it should show 1013 hpa.

Have to do one point calibration (OPC)?

Can you help me??

7 REPLIES 7
GPapa.6
Associate II

Any help??

Miroslav BATEK
ST Employee

What is your reference (how do you know that the correct value is 1013hPa)?

Absolute accuracy over temperature of the sensor without OPC is 1hPa so there is something wrong.

Legacy member
Not applicable

Hello,

Are you measurung common atmospheric pressure? Are you aware that the air pressure value that is usually published (news, weather stations etc.) is a calculated sea-level pressure value (to be able to easily compare with other places)?

https://en.wikipedia.org/wiki/Atmospheric_pressure#Mean_sea-level_pressure

David

GPapa.6
Associate II

Hello again,

the value that the sensor gives me after the conversion of absolute pressure in the sea level it's wrong.

The absolute pressure i read from the sensor is 973.7 hpa and the temperature is 22.3, i used the mathematical formula:

0690X000006COU3QAO.bmp

to calculate the pressure in the sea level. My location has 45 meters altitude and i measure absolute pressure 973.7 hpa with this data the computational pressure on the sea level is 980.5 hpa.

I compared the result with the nearest weather station in my area and it was a mistake, the weather station wrote 1020 hpa.

Why it exists such a diviation;

Miroslav BATEK
ST Employee

How far is the reference weather station?

Aren't you inside a building with air condition?

Do you use you own HW or a ST development board?

GPapa.6
Associate II

1) The weather station is 150 meters away.

2)No, the measurements are made at temperatures of 18-22 ° C.(environments)

3)I use my own HW.

I tested the sensor MS5611 and i measured absolute pressure 1006.8 hpa unlike the sensor LPS22HB which measures 970.5 hpa.

The sensor LPS22HB if the temperature changes the pressure is changing unlike the sensor MS5611 which remains stable in temperature change.

Why it exists such a diviation;

Miroslav BATEK
ST Employee

A mechanical stress can cause a deviation.

Please check application note AN4672 Hardware guidelines for system integration.

https://www.st.com/content/ccc/resource/technical/document/application_note/group0/d2/9c/f5/87/22/c3/4b/6e/DM00170606/files/DM00170606.pdf/jcr:content/translations/en.DM00170606.pdf