Rules are commonly used for measuring distances and guiding straight lines. Their basic design has been around for thousands of years. Although there are different types, and many have additional features, this simple tool is still fairly common. However, there have been developments in measuring instruments over the centuries and there are various alternatives which can be used for measuring distances and guiding straight lines.
Alternatives to rules for measuring distance
Standard rules are designed for measuring linear distances (widths and lengths). A quality rule should be accurate to its smallest division, but, they rely on the user handling and reading the rule correctly to provide this accuracy. There are other tools which can also be used for measurements.
For more information see: How to measure accurately with a rule.
Measuring tapes
Tools like measuring tapes, or tape measures, have been around for almost as long as rules. They work in the same way but can measure along curves or around corners, and can usually measure longer distances than a standard rule. A simple measuring tape is a flexible strip with measurements marked onto it, they are commonly used by tailors and dressmakers.
Spring measuring tapes, sometimes called retracting tape measures, are a development from the simple measuring tape. They consist of a measuring tape which is coiled inside a case, so they can be easily stored and carried. They can be locked at any extended position and once released the tape will retract back into its case. This design means long strips can be coiled into a relatively small size.
Calipers
Calipers are used to measure small distances between two symmetrically opposing sides of an object. There are various types of calipers, and they’re used for precision. They work well with objects which would be difficult to measure with a rule, such as screw or nail heads. For measuring even smaller distances, a caliper called a micrometer can be used.
Combination set squares
These combine a rule strip with a protractor, square head, and centre head. The rule strip can be used the same way as any other rule, to measure or guide straight lines. The other parts measure and set specific angles, which makes them more versatile than a standard rule.
Measuring wheels
For measuring longer distance across the ground or a similar surface, you could use a measuring wheel. These have a wheel attached to a handle. The circumference of the wheel is a specific distance so that each full rotation will measure that distance. They usually have a click which sounds every time a full rotation is made. They can also be called surveyor’s wheels, trundle wheels, clickwheels or hodometers.
Alternatives to rules for producing straight lines
The first straight lines for construction and other purposes would have been produced with a material, such as string, being pulled taut. In Medieval construction dyed string was stretched tight over wooden beams to mark straight lines on them.
Rules and rulers are commonly used to aid with creating straight lines, but there are other things available, and any object with a straight edge can guide a drawing implement to produce a straight line.
Measuring instruments with straight edges
Many of the tools which can be used to as an alternative to rules for measuring also have straight edges. Combination set squares, folding squares, carpenters squares, try squares, set squares, and sliding bevels, as well as many calipers, have straight edges which could aid with producing straight lines.
Straight edge rules
Straight edge rules are used specifically to draw or scribe straight lines or for checking the straightness of a surface. They may have gradation marks on them, but often have no markings as they are not usually used for measuring. They often have a holding handle so they can easily be held with their edges clearly visible. They are sometimes just called straight edges, and most rules are a type of straight edge.
Marking out gauges
A marking out gauge is a tool usually used for marking straight lines in woodwork, and sometimes metal work. They will only be able to produce a straight line if the edge of the workpiece is straight, because they have a guide which runs along an edge. There are a five types of marking out gauge: marking gauges, panel gauges, cutting gauges, wheel gauges and mortise gauges.
Alternatives to digital angle rules for measuring angles
Digital angle rules are primarily used to measure specific angles. There are other tools which could be used to do this.
Protractors
A protractor is a simple instrument for measuring angles. They’re either circular or half-circular, with degree measurements marked on them. Normally they’re transparent and made from flat plastic. They can be lined up on a 2D angle to measure it, or used with folding rules to measure angles. They are not suitable for measuring 3D corners like digital angle rules can.
Digital angle finders
These closely resemble digital angle rules, but they can only be used to measure angles – they can’t measure straight distances. They have two straight strips which move against each other, the same as a digital angle rule, and the angle is displayed on a small screen. They also incorporate spirit levels, so ground levels can easily be determined. Digital angle rules don’t have this feature.
Digital protractors
These are sometimes called digital angle gauges. They can be a simple-looking small box which will read the angle it is tilted at from a set level. These can be used from any set position, whether on a surface or not, but they can not be locked into position like a digital angle rule.
Try squares and mitre squares
Mitre and try squares are used to assess specific angles. They consist of two strips, a blade and a stock, which are set to either 90 degrees or 45 degrees. The strips don’t usually have any gradations marked on them and they can’t be moved to gauge different angles.
Sliding bevels
Sliding bevels are mainly used to transfer existing angles from one place to another. They have two strips, similar to try and mitre squares, which can be adjusted to gauge different angles. Unlike a digital angle rule they won’t tell you what the angle is without using a protractor, or similar tool, to measure it.
Folding squares
These measuring tools are usually larger than most standard rules or angle gauges. They can be folded and set to gauge angles, specifically 90 degree angles, and then folded to one length for storing. They are usually used for larger scale measuring and marking tasks, for things like construction.