Voltmeter's effect on a constant current circuit
Hi,
I am using a TDK Lambda Genesys Gen 150-5 digital programmable power supply to power a load in constant current mode.
The voltage is set to 32v and the current is current limited to either 65mA, 390mA or 780mA.
In all three currents the load requires around 29v to run at their respective currents.
The power supply drops the voltage down to achieve the current load that is sent.
What I need to do is measure the voltage at which the power supply is regulating at.
The Power supplies built in voltmeter is not accurate enough so I am using a Fluke 8846A precision multimeter wired in parallel to the circuit to measure the voltage.
My question is: Will the fluke meter hooked up to the circuit affect the voltage in test and produce an inaccurate result? Or is the input impedance too high on the fluke to make a difference?
I am trying to grab a consistent 0.1v difference but would like to achieve an absolute accuracy of at least 0.01 and hopefully 0.001v.
The Fluke is a 6 & 1/2 digit multimeter.
