Selecting Analog Cables

None whatsoever, provided the loop resistance is less than the maximum for the voltage and the transmitter manufacturer's instructions. Provided they have low enough resistance, two bits of wet string would do for circuit conductors.....

Hi there,

When sizing a cable there are a few things to bear in mind.

1. Total length of the loop.

2. Instrument impedance, inductance and capacitance.

3. Cable (conductor) impedance, inductance and capacitance.

You then need to look at your local regulation as well as the instrument manual. Here you will find what the maximum percentage volt drop across the loop may be as well as the maximum impedance, inductance and capacitance across the loop may be for the instrument to function.

You can then look at your cable data sheet and calculate these factors very simply from there on. The bigger the conductor size, the less the impedance, inductance and capacitance will be.

Regards,

Craig

Use double shielded coax or triax for best low noise results.