Tank monitor
FIG. 1 is a top plan view of the tank monitor embodying the invention; 
     FIG. 2 is a front view thereof; 
     FIG. 3 is a rear view; 
     FIG. 4 is a bottom view; 
     FIG. 5 is a right side view of FIG. 1; and, 
     FIG. 6 is a left side elevational view of FIG. 1.