Facts about vials
The fluid-filled containers that give you a level reading are called vials. The liquid in the vials is usually oil or alcohol so that the air bubble inside can move freely.
Different vials might appear similar at a casual glance. But the design and mounting of vials differ a lot between different brands, resulting in different accuracy and precision.

Sturdy mounting for higher sensitivity
How the vial is mounted in the profile determines how sensitive it is to temperature and shock. On the best spirit levels the vials are fitted with a tensioning wedge, ultrasound welding or brackets for maximum accuracy and sturdiness.
Our vials are filled with oil
The liquid in Hultafors’ vials is a coloured low viscosity oil mixture. This gives the bubble optimal freedom of movement and makes it easy to read.
Magnifying lens facilitates reading
To facilitate reading, extra fine vials feature a magnifying lens to make the bubble appear larger, and rings that go all the way round for accurate readings from any position.
A luminescent reflector behind the vial helps in dim light conditions.
Unaffected by temperature and UV light
The oil in Hultafors’ vials is highly resistant to both ultraviolet light and fluctuations in temperature and gives a consistent bubble movement from -20° C to +60° C. In case of shock, the temperature resistance also prevents bubbling.
Antistatic vials for accuracy
Static electricity can cause some spirit levels to give inaccurate readings. Therefore Hultafors spirit levels feature antistatic vials.