What brand of densitometer is it. I have not seen a densitometer that shows "V". You probably need to contact the manufacturer to find out.
Originally Posted by Chan Tran
The color densitometry chapter in Todd an Zakia describes Equivalent Neutral Density (END) and mentions that if you know the END and Analytic Spectral Density of a dye, you can take that ratio and use it in the ASD/ISD conversion matrix to calculate END.