Comparison of voltammetry and digital bridge methods for electrical resistance measurements in wood

The comparison of accuracy and ease of operation was made between voltammetry and digital bridge method for electrical resistance measurement in Populus davidiana wood specimens and the factors influencing voltammetry were examined. The results showed that current types, waveforms, voltages and frequency had different effects on the resistance values of voltammetry. The measured DC resistance decreased with the increasing voltage. DC resistance presented a turning point at the voltage of 8 V, while AC impedance remained constant over the entire voltage range. The effects of waveform on resistance was minor. No remarkable difference in resistances was found between the two methods above fiber saturated point (FSP) and voltammetry was relatively stable below FSP. The relationship between MC and resistances confirmed the previous findings from other scholars. Compared to the digital bridge, the voltammetry of AC with 1000 Hz sine waves was found to be the superior method for wood resistance measurement.