LDC 1000 length measurement sensor up to 6 meters

Magnus Eriksson

Hello

I'm thinking of using the LDC1000 to measure a distance of up to 6 meter with a resolution of more than 0.1mm per meter. The measurement pattern is supposed to be the same pattern as in the datasheet.

1: Is it possible to use more than one coil connected to one LDC1000? BOM cost optimization.

2: When I have played around with the EWM the distance to the measurement object seems to be critical to get a good knowledge of the measurement object. I was thinking of using three coils in a row to detect the pattern and somehow get rid of the distance tolerances to the measurement object. Is this a good way for compensate for distance tolerances or have any one else found a different solution?

3: how long coil radiuses most I have to get the resolution that I need?

Best Regards

Magnus

over 9 years ago

0 Don Liu over 9 years ago

TI__Intellectual 1290 points

Hi Magnus,

If I am right, you are trying to do a lateral measurement with 60,000:1 accuracy. Although LDC1000 has enough resolution for this, the accuracy requires at least 10x stability in the Z-axis control. It is probably not practical.

Best regards,

Don

0 Magnus Eriksson over 9 years ago in reply to Don Liu

Prodigy 40 points

Hello Don

No lateral measurement. x measurement. I was think of measure a pattern that is looking like a head of arrow that is 6 meter long. The same shape that is in use for the implementation of the angle sensor but here stretchout in a stright line of 6 meter.

Best Regards

Magnus

0 Don Liu over 9 years ago in reply to Magnus Eriksson

TI__Intellectual 1290 points

Hi Magnus,

If the "arrow" is 6M long, and you need to resolve down to mm, you need to maintain the distance from the coil to the arrow very precisely, in the order of um.

Best

Don

0 Magnus Eriksson over 9 years ago in reply to Don Liu

Prodigy 40 points

Is it possible to calibrate the z axis tollerance by adding more coils or is the sensor that sensitive to z axis tollerances?

0 Don Liu over 9 years ago in reply to Magnus Eriksson

TI__Intellectual 1290 points

Magnus,

For your application, the compensation will not work. The temperature coefficient and the variation of the L and C easily exceed the accuracy that you want to maintain.

Best regards,

Don

0 Magnus Eriksson over 9 years ago in reply to Don Liu

Prodigy 40 points

Okay thank you for your help.

Best Regards

Magnus

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LDC 1000 length measurement sensor up to 6 meters