Apparatus and method for testing the level of an item in liquid

Apparatus for measuring the level of an item in a liquid comprising first and second light-transmitting cylinders, first and second pistons associated with said first and second cylinders, respectively, a third cylinder, a third piston associated with said third cylinder, lever means, means coupling said first and second and third pistons to said lever means, first and second conduit means in communication with said first and second cylinders, respectively, a source of indicator solution, third conduit means for effecting communication between said second and third cylinders, fourth conduit means for effecting communication between said source of indicator solution and said third cylinder, motor means for actuating said lever means to cause said first and second pistons to draw liquid into said first and second cylinders, respectively, through said first and second conduit means, respectively, and for causing said third piston to eject indicator solution into said second cylinder through said third conduit means, and for causing said first and second pistons to eject said liquid and a mixture of said liquid and indicator solution from said first and second cylinders, respectively, and for causing said third piston to draw indicator solution into said third cylinder through said fourth conduit means from said source of indicator solution, light source means for transmitting light through said first and second cylinders, and detector circuit means for providing an output based on the different light transmissions through solutions in said first and second cylinders.