I got an eseco speedmaster 1400 color analyzer but I don't know how to use it. There was no manual. Does anyone know where I might find a copy of the manual? It seems pretty straightforward so maybe somebody can explain how it is typically used. There is a switch for R, G, and B, then C, M, and Y potentiometers and an LED display. I could probably figure out how to use it as an enlarging meter for B&W...would I just use the blue channel?