How to measure this capacitance using a capacitance meter

[nst.john]

I posted this picture in another thread but I now have a specific question for the capactance measurement between both transducers (the middle C). How can I measure the capacitance of this using an LCR meter. Where should the leads be put and what are some averages of a capacitance I should be getting for transducers about 4-5inches apart with a 3 inch diameter apporximately with a glass beaker with water between them? Thank you for your help!

 

[tech99]

I posted this picture in another thread but I now have a specific question for the capactance measurement between both transducers (the middle C). How can I measure the capacitance of this using an LCR meter. Where should the leads be put and what are some averages of a capacitance I should be getting for transducers about 4-5inches apart with a 3 inch diameter apporximately with a glass beaker with water between them? Thank you for your help! View attachment 86010

Two metal plates of the dimensions you mention may give about 30pF with the water dielectric. I suggest joining the two leads of each transducer together. You could also experiment using metal plates. C= 0.088 kA/d (where C is the capacitance in pF, A is the area of one plate in cm2, d is the spacing in cm and k is the relative permittivity of the dielectric, about 81 for water).

 

[nst.john]

Sounds like a plan. Thanks so much for the help