HP206C barometer - the values vary with each reading

Hello,

I want to have an accurate relative altitude so I bought the Grove - Barometer (High-Accuracy) Sensor with the HP206C high-accuracy. But I am disappointed about the values are read.

I am using the example program that display the temperature, pressure and altitude each 1 second. I expected to see closed values between 2 acquisitions because of the high accuracy of the sensor (0.01m) but I see large variation. For instance, you can see several times in the serial log below a change in altitude of about 2 meters whereas the sensor does not move.

I tried to configure the sensor using HP20X_CONVERT_OSR4096 instead of HP20X_CONVERT_OSR1024 and changed OSR_ConvertTime to 150ms. I do not see a difference.

Could you give some tips about how read accurate values?

****HP20x_dev demo by seeed studio****

Calculation formula: H = [8.5(101325-P)]/100 

****HP20x_dev demo by seeed studio****

Calculation formula: H = [8.5(101325-P)]/100 

------------------

Temper:
20.08C.

Filter:
14.70C.

Pressure:
888.47hPa.

Filter:
545.01hPa

Altitude:
1095.89m.

Filter:
547.95m.

------------------

------------------

Temper:
20.08C.

Filter:
16.75C.

Pressure:
888.26hPa.

Filter:
797.68hPa

Altitude:
1097.83m.

Filter:
840.24m.

------------------

------------------

Temper:
20.09C.

Filter:
18.81C.

Pressure:
888.21hPa.

Filter:
848.71hPa

Altitude:
1098.30m.

Filter:
1004.95m.

------------------

------------------

Temper:
20.09C.

Filter:
19.57C.

Pressure:
888.26hPa.

Filter:
876.63hPa

Altitude:
1097.83m.

Filter:
1061.35m.

------------------

------------------

Temper:
20.09C.

Filter:
19.99C.

Pressure:
888.48hPa.

Filter:
883.73hPa

Altitude:
1095.80m.

Filter:
1083.13m.

------------------

------------------

Temper:
20.08C.

Filter:
20.04C.

Pressure:
888.26hPa.

Filter:
886.35hPa

Altitude:
1097.83m.

Filter:
1092.42m.

------------------

------------------

Temper:
20.08C.

Filter:
20.07C.

Pressure:
888.26hPa.

Filter:
887.81hPa

Altitude:
1097.83m.

Filter:
1096.13m.

------------------

------------------

Temper:
20.09C.

Filter:
20.08C.

Pressure:
888.35hPa.

Filter:
888.13hPa

Altitude:
1097.00m.

Filter:
1096.64m.

------------------

------------------

Temper:
20.09C.

Filter:
20.09C.

Pressure:
888.31hPa.

Filter:
888.24hPa

Altitude:
1097.37m.

Filter:
1097.09m.

------------------

------------------

Temper:
20.09C.

Filter:
20.09C.

Pressure:
888.09hPa.

Filter:
888.15hPa

Altitude:
1099.41m.

Filter:
1098.40m.

------------------