Figure 6. Conductance levels of the five different melted snow samples collected in January-March, 2010 in Beijing measured at different modulation frequencies of 1 kHz to 100 kHz by a lock-in amplifier operated at a modulation amplitude of 50 mV.

A LabView program was develoepd to automatically modify the output modulation frequency; data points represent averages of 500 measurements (1 measurement per 300 millisecond); the arrow indicates the conductance transition at the frequency of 10 kHz.