A professional who tends equipment that fills glass vials with alcohol or ether solution and leaves air bubble to form vials used in tools and instruments to determine levelness. Responsibilities include:

• Fills rack with vial-filled cups and lowers rack into tank of solution.
• Lowers weighted glass cover and moves lever to turn on air pressure.
• Sets timer for designated time cycle.
• Shuts off air and raises cover when bell rings.
• Compares bubbles in random sampling of filled vials with master vial for conformance to size.
• Refills vials or lets vials stand to evaporate excess fluid to regulate size of bubble.
• Pours solution from jug into tank to replace used fluid.