Question about cable capacitance value

Cable capacitance

What is it?
I´m using a cable to measure the impedance of a solution. There are about 5 cables and a shiled that is shorter than the cables. That is:
[instrument] [3m of Shielded cables ] [50cm of UNshielded cables] [Solution]

The cable is supposed to have 300pF capacitance. I don't understand that specification; capacitance relative to what? Between cables? Between Shiled and cables?. How can I measure it? (I have a scope and a sig. gen.)

The measurements are low freq (DC - 10KHz). Would it be troublesome to have a cable with such capacitance (300pF)?.
Is the capacitance of the cable important in designing low level measurements (1uV) instruments (in the BW specified above)? Why?

Of course, I don't expect a full answer here, just some basic guiding aspects and some links to free pdfs .

Best regards,

Re: Cable capacitance

The rated or specified capacitance is between the two conductors carrying the signal. You can correct for this by taking the measured value of solution impedance and converting it to an admittance. Then subtract the cable capacitive admittance from this value and then convert back to impedance.

Your using an oscilloscope will allow you to measure magnitude and phase. From this you can convert to rectangular format for the above calculations.

Re: Cable capacitance

Dtenks flatulent.
Any other tips about the other questions, please? Maybe some "Further readings..." links.
I am on my firsts years of electroincs eng. It is diffucult to me to apply basic concepts to real measurements setups. I am particulary interested in living cells electrical measurements. That is:
- Extremely low SNR
- Small votages (1uV - 1mV)
- Near DC measurements (low freq noise is driving me crazy)

Re: Cable capacitance

Keithley company http://www.keithley.com/support makes low level measurement equipment. Look on the left of the page for application notes and articles.