of the float 30 contacts the upper surface 29 of the fluid 12 and buoyed thereby at this point the distance that the measuring wire 18 has travelled is measured by the device 16 and displayed as an indication of the volume of fluid 12 in the reservoir 14 to provide rotational stability of the float 30 as it is lowered out of the guide 24 a pair of vertical wires 52 and 54 are secured at an upper end to the plates 44 and at a lower end to a guide wire tension weight 56 that is positioned on the bottom 22 of the tank 14 the wire tension weight 56 is of sufficient weight to maintain the wires 52 and 54 taut so as to provide a sufficient guide for the float 30 while it is lowered or raised relative to the upper surface 29 of the fluid 12 once the measurement of the fluid level has been accomplished the float 30 may be raised from its position floating on top of the upper surface 29 of the fluid 12 to within the guide tube 24 whereupon it may be removed through the ball valve 32 the removal of the float 30 is accomplished by reeling in the measuring tape 18 upon actuating the device 16 as the float 30 is raised from the surface 29 of the fluid 12 the side 34 remains substantially parallel to the surface 50 as the float 30 engages the radial portion.