Optimal accelerometer for measure accelerations less than 0.2g?

[praveen1]

I want to measure movement in the z-axis for accelerations less than 0.2g. Which accelerometers should I explore?

[TomasVaverka]

Hi Praveen,

Could you please elaborate a bit more on your application and requirements?

If you are looking for a low-g, Z-axis accelerometer with signal conditioned voltage output, then I would recommend considering the MMA1270KEG(R2). This product measures acceleration with a full-scale range of ±2.5g with sensitivity of 750mV/g.

I would also recommend considering the new FXLN83xxQ family of 3-axis analog accelerometers offering high sensitivity at low power consumption. For more information on this product as well as other (digital) devices (MMA8451Q, FXLS8471Q, MMA8491Q), please refer to the fact sheet.

Regards,

Tomas

PS: If my answer helps to solve your question, please mark it as "Correct" or “Helpful”. Thank you.

[praveen1]

Thanks Tomas. Here are more details about my application:

The accelerometer will move about a meter along a straight line. The max acceleration is probably no more than 0.5g, the average being 0.1g or less. The accelerometer will accelerate for some time and then decelerate and come to a stop and then move backwards.

I would like to accurately measure the acceleration and distance traveled each time as that will vary each time that this movement is made.

I am building a prototype and in the beginning like to get digital output from the accelerometer. I am interfacing this accelerometer to a RasPi.

I looked at the datasheets and MMA8451Q looks like the one to try. I know that measuring distance is a big challenge but in the constrained environment like the one that I have described, do you think that it is possible. I can run some processing algorithms on RasPi. Do you have any suggestions on the post processing algorithms that I should explore?

Thanks

Praveen

[TomasVaverka]

Hi Praveen,

The MMA8451Q is a good choice for such an applicaton as it is arguably the lowest noise digital part in the market with very good temperature performance and 14 bits of resolution. Select the lowest possible ODR, set the ±2g range and use both Low Noise (LNOISE bit = 1) and High Resolution (SMODS = 1) modes for the best noise performance. It is also recommended using an embedded high pass filter to compensate a tilt error.

Hope it helps.

Regards,

Tomas