The tubular levels can be fastened using the two holes.
- Form A: one sight window
- Form B: three sight windows
- Sensitivity in angular minutes for 2 mm bubble travel
- Green filling
Tubular bubble vial glass.
Nickel-plated and high-gloss polished. Form B: black anodised.
Bubble levels are used as a type of zero indicator instrument for checking horizontal inclination in e.g. spirit levels, inclinometers, metrology instruments and machine constructions.