How-To Guide

TWO CHANNEL MEASUREMENTS

MEASURING SMALL RESISTANCES / CALIBRATING A CURRENT SHUNT

Your N2-Neuron is capable of reading any two of its three channels simultaneously.

The N2-Neuron can be used to measure small resistances in a

live circuit. The meter simultaneously measures the current and

the corresponding voltage with the precision voltage channel

(Ω), and then nds the slope to calculate resistance.

This can be done with either the internal current shunt or an

external current clamp. Using a current clamp allows the

measurement to be done without breaking the circuit and allows

for test currents above 10 Amps.

Wire the meter in as shown and enable the measurement mode.

Apply a test current and run the analysis.

The analysis works best with several points along the curve.

Therefore, the optimal test current has a large magnitude and a

strong time-varying component below 1kHz. Often this test

current can be the current already present within the system due

to normal operation. For example, an AC system’s steady state or

a DC systems startup transient may provide sucient data.

Measurements using the internal current shunt will experience a degree of cross-talk due to the impedence of the Common lead. Other

measurement types will also experience this cross-talk, but it should be negligible.

NOTE

FIGURE 7 CURRENT CLAMP AND CURRENT SHUNT COMPARISON