FDC1004: conductive liquid

laurence babour

Prodigy 50 points

Part Number: FDC1004
Other Parts Discussed in Thread: FDC2214

hi,

I want to measure capacitance of an ink (about 10-15pF) and I want to use FDC1004. Can we use it?

regards,

Laurence

over 7 years ago

0 Chris Oberhauser66 over 7 years ago

TI__Genius 14270 points

For conductive liquids, the FDC2214 may be a better choice.

Regards,

ChrisO

0 laurence babour over 7 years ago in reply to Chris Oberhauser66

Prodigy 50 points

HI Chris,

Thanks for this information. May I have more information of using FDC2214 instead of FDC1004 for conductive liquids, such as physical explanations?

thank you in advance

Regards,

0 Mathew Maher over 7 years ago in reply to laurence babour

Intellectual 460 points

I second this request!

Looking to detect changes in oil quality over time. Typically would use conductivity measurements, but can't help but feel a capacitive solution may be worth a look.

Mat

0 Yibo Yu over 7 years ago in reply to Mathew Maher

TI__Expert 8050 points

Hi Laurence and Mathew,

Thank you for your interest in TI's FDC devices.

The FDC1004 is based on the switched-capacitor architecture. The excitation frequency is 25 kHz. For conductive liquids, the charge may dissipate before it can be measured. However, it can still work for liquids of low conductivity (even some types of ink).

The FDC2214 is based on the LC-resonance architecture and it can operate in the MHz range. Therefore it can be used for conductive liquids.

Regards,
Yibo

Sensors

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FDC1004: conductive liquid