Unsmooth linear acceleration data

[Jim123321]

Hi! I'm working on an experiment that requires me to collect acceleration data. I put my phone on the object and get the acceleration data by the phyphox app. However, when processing the data, I often find some data points behave strange, such as suddenly drop dramatically when that trend of other acceleration points are at upward trend. Is this the app problem or the inaccuracy of the builtin accelerometer or the problem of my experiment? I think at least I should get a smooth acceleration data.


For example, this is the whole experiment data plot, the data points do follow some trend (I added a screenshot):
   


However, when I zoom in, some data points are strange sometimes(I added a screenshot).
   

[Jens Noriʇzsɔɥ]

Are the screenshots mixed up: the zoomed-in graph has a broader range of t and acceleration…? What do you mean by “strange”? Perhaps I missed something: for me, there appears to be just some noise on top of the data…

[Jim123321]

Are the screenshots mixed up: the zoomed-in graph has a broader range of t and acceleration…? What do you mean by “strange”? Perhaps I missed something: for me, there appears to be just some noise on top of the data…

Oops I placed the picture in the wrong order. I fixed that now. 
In my other similar experiment, when the acceleration is larger (larger amplitude and same period), there’s no such noise and the data give a smooth curve, so I’m wondering how to remove the noise in the data above.