Spirit Levels

Box levels are so called because of the shape of the profile’s cross section, which is rectangle and hollow. Due to the square build construction, box levels have four points of strength and a higher resistance to torsion. Box shaped levels offer better features and higher precision such as solid acrylic vials, durable aluminum profiles, and ergonomic handles.

Aluminum die casting is a manufacturing process that produces accurate, pre-defined, smooth and textured-surface metal parts. The biggest advantage of aluminum die cast spirit levels is their strength, and durability.

The I-beam derives its name from the shape of its profile’s cross section, that resembles the letter I. I-beam levels are lightweight and economical, making them attractive options. While they will never reach the professional accuracy and durability of a box level, the I-beam level has its place on construction sites.

Named for the shape of its rounded ends, torpedo levels are typically 6"-12" (15 cm - 30 cm) in length. They are also sometimes referred to as toolbox levels due to the way they can easily be stowed inside.

This type of spirit levels is used to level and plumb posts and pipes. The level will host both horizontal and vertical vials and will be equipped with a strap, magnet or both to secure the level to the surface. It generally presents itself as a two-sided molded plastic that forms a 90° angle.

Gradient spirit levels are designed for measuring slopes and angles. These types of levels are typically created as a variation of other box levels, that have additional vials or other components for multi angle measurement.

These levels derive their name from the additional digital components that is added to the traditional spirit level vial. Most digital box levels will house the digital module and LCD screen inside the frame. Digital levels are typically less precise than spirit levels but allow for easy measurement of various angles. Because of its electronic nature, it is crucial the level will offer a rating of IP54 and up.

Combining a small and compact structure to fit in a pocket, with a basic single or dual vial, pocket levels are used for small jobs or at DIY projects.

Screeds are best suited for leveling soft media like cement, sand or mud on large-scale projects or just flattening and evening out smaller surfaces. They can be made from reinforced aluminum box profiles, high purity magnesium, magnesium alloys, wood, or even plastic. The aluminum box profiles are easier to clean and are engineered to be stiffer and straighter, so they are less prone to bending.

Accuracy tolerance refers to minor and microscopic variations/errors that occur during the production process. It represents a deviation from perfect accuracy for a given length (usually 1 meter or Inch) Professional spirit levels have an accuracy tolerance of 0.5 mm/m (0.0005 In/In) while the DIY market sports an accuracy tolerance of 1 mm/m (0.001 In/In). Kapro’s levels offer ±0.5 mm/m (0.0005 In/In) vial accuracy. Kapro’s accuracy tolerance is VPA certified by the Independent German laboratory.

Every Kapro level is tested for perfect calibration before shipment. However, with time, some variations might occur. Here is how you can easily check your level's calibration: - Position your level on a clean flat vertical or horizontal surface. Check the bubble position - Mark a line at the end of the level - Mark an additional line at the side of the level - Turn the level 180 degrees; end to end (horizontal position) or side to side (vertical position) - Line the level to the marked lines and check the bubble position again - Any deviation in bubble position, relative to the initial position indicates a calibration inaccuracy

Reversibility refers to the accuracy of the level when used for inverted measuring. Not all levels are accurate in the reversed position. Ensuring reversibility requires special production, assembly, and calibration. Kapro offers a wide range of levels with full reversibility and accuracy of ±0.5 mm/m (0.0005 In/In) in both normal and reverse leveling positions.

The sensitivity of a bubble is defined by its radius. As sensitivity increases, the level will be more precise; but the bubble will be harder to stabilize. The standard sensitivity in the spirit level market is of 10 mm/m (0.01 In/In) which means that if you raise one end of a 1-meter-long level by 10mm, the bubble will move by 2mm if the radius of the vial is 200mm.

The way a vial is mounted on the profile has a direct effect on the durability of the spirit level. Epoxy locking of vial housings and vials guarantees that the level can better withstand the rough workplace environment and retain its factory-calibrated accuracy for the life of the level. Most Kapro Spirit levels are epoxy locked.

The reading lines on the vials are crucial to the proper use of any spirit level. A continuous solid line that will not move is ideal, and Kapro takes pride in the fact that all solid acrylic vials have reading lines painted inside the vial, to ensure maximum accuracy. Other vials in the market have thin metal springs that are inserted into the vial and act as reading lines, with a potential of discontinuity and potential movement compromising the spirit level's accuracy.

Most vials have just one reading line on either side of the bubble to allow the measurement of a leveled surface. Multiple lines allow the determination of inclination and can support setting slopes when needed. Kapro offers a variety of vials, ranging from 1 to 3 pairs of reading lines, depending on the level and its usage goal.

Bubble size can have a potential impact on the accurate reading. The bubble should not exceed the reading lines when the level is in room temperature and is placed on a true leveled position. Temperature changes can cause bubble size changes, with higher temperatures shrinking, and lower temperatures expand the bubble's size. Kapro tests its vial in a variety of temperatures to ensure bubble size is maintained across the working temperature range.

The two basic types of vials in the market today are solid acrylic and cylindrical vials. Injection molded cylindrical vials are the most basic, typically for DIY projects where absolute accuracy is less critical. Solid acrylic vials are usually twice as accurate, stronger, shockproof and capable of withstanding a harsh work environment giving it superior longevity. Kapro offers a lifetime warranty on solid acrylic vials which are guaranteed to be accurate, and resistant to fog, leakage or breakage.

All Kapro's vials are filled with a liquid substance of hydrocarbon fluid, a molecule with carbon and hydrogen chains. This fluid allows the air bubble in the vial to move easily within it and provide a colored background to increase visibility of the bubble. If the color in the liquid fades due to UV rays, the level stays accurate, but its readability decreases. This hydrocarbon fluid is resistant to extreme temperatures from -20˚ to 60˚, allowing for greater stability and more accurate measurements. Kapro offers UV resistant vials with strong resistance to the fading effects of sunlight.

The vial visibility is crucial for professional precision, and several factors can affect it. The color contrast of the liquid as well as the orientation of the vial can result in large deviations. From magnified vials to the patented OptiVision® vial, Kapro brings you the most visible vials in the market today.

Magnified vials are solid acrylic vials that have been treated to project a bubble image that is 33% larger than traditional vials. The 270° visibility provides improved readability which will facilitate a quicker read on the job. Kapro offers the magnified vial on a variety of spirit levels.

The angle finder has gradient markings that help you transfer angles and re-post measurements. The unique rotating dial allows for an easy adjustment of the vial according to need.

The OptiVision® patented vial technology creates highly visible red bubble edges for exact placement between the reading lines and optimal visibility under bright and low light conditions. In addition, the tilted angle of the vial gives a direct line of sight to the bubble with no distortions for additional visibility. Combined with excellent UV resistance, the OptiVision® vials are guaranteed to maintain visibility for a long periods of time.

The Plumb Site® Dual View™ vial offers both a front view of the vertical vial as well as the traditional side view via its unique reflection system. This allows a complete field of vision for a true plumb reading without parallax error, neck, or back strain, and helps getting the job done faster and easier.

The Swivel Plumb Site® solves the problem of getting accurate readings from difficult angles or heights. With five times wider view of the vertical vial, it allows plumb reading without parallax error, neck, or back strain.

A typical spirit level is made of hollow aluminum profile. Once it is punched, its tensile strength is lowered, especially around the horizontal vial hole punch. Some levels have ribs or a bridge that strengthens the structure of the profile. In some cases, unique asymmetric aluminum profiles are used to add mechanical strength.

Aluminum profile wall thickness is an important element of the box and I-beam spirit levels as it affects the weight and the strength of the level. On average, the wall thickness of spirit level profiles range between 1.2 and 2.1 mm (0.04 to 0.08 In). Kapro's professional box levels wall thickness ranges between 1.8 to 2.2 mm (0.07 to 0.09 In).

A finely milled base provides a guaranteed flat surface and ensures maximum accuracy of the spirit level. Not all levels have a milled base, typically due to one of two reasons. Milling is forgone when it would compromise the strength of a particularly thin level level, or else compromise the coating. Kapro offers a variety of spirit box levels with one and two milled surfaces.

Most box level profiles nowadays offer either an anodized or electrostatic powder coating with durable epoxy polyester paint. Both coatings are water resistant, allow for ease of cleaning, and are very durable. Differences in quality may arise from the thickness and smoothness of the coating application on the base of the level. It may affect its precision to a degree. Kapro's meticulous quality control procedure allows for excellent coating of the spirit levels, while maintaining accuracy.

Box level handles are an important feature as they allow an easy, comfortable hold of the level body, especially longer models. Many levels have hand grips, but some are lacking an ergonomic design that would allow for prolonged usage without any implications. Kapro offers large rubber coated handles on all professional box and I-beam levels.

Shockproof end caps protect the level by absorbing the impact caused by drops and falls. End caps can be made of rubber, bi-material or plastic. Rubber and bi-material end caps are the most popular materials and offer excellent shock resistance.

A wall grip is a unique Kapro feature that allows for easy one handed use. The rubber grips cling to walls as you level and mark.

The v-groove at the base of a level is there to facilitate the placing of the spirit level on circular surfaces such as pipes or posts. Some box levels offer a magnetic base with a V-groove which allows hands-free operation while leveling pipes or posts.

Most magnetic spirit levels have either ceramic magnets or rare earth magnets. These magnets differ in their strength and rust resistance. Rare earth magnets are the strongest and most permanent magnets in the world. Also known as neodymium magnets, they are stronger than ceramic magnets, less brittle, and more expensive. Most magnetic Kapro spirit levels have rare-earth magnets (N35/N45). The strength of each magnet varies between 50 to 70N each.

Shock-absorbing rubber anvils were designed to protect the level from trowel and mallet tapping, thereby safeguarding the level's accuracy. These anvils are composed of a combination of rubber and bi-material that are chosen for their exceptional shock resistance characteristics.