List of Measuring Tools for Length

When measuring length, there are several choices available depending on what you are measuring and how precise you need the measurements to be. Each tool is used for a specific job or function, and it is important know which one to choose.

Plan Scale

A plan scale is used when determining the length on a plan drawing. It measures linear, square and volume of a drawing. A plan scale has a roller that is moved about the drawing that is being measured. It can be used on blueprints, black-and-white copies and hand drawings. The tool primarily is used when a CAD system is not available or plans need to be read on the spot.

Measuring Tape

A measuring tape is a flexible metal that rolls into a casing. Tape measures come in a large variety of styles and can measure 50 to over 300 feet. Some also are available in digital format, have voice-recording features, diameter readings and dual reading options--such as reading both metric and non-metric. Metal tape measures have a metal clip on the end that protrudes from the casing to hook on to edges and corners.

Straight Ruler

A straight ruler is made of numerous materials, such as wood, plastic and metal. It is long and straight, and measures in inches, feet, millimeters and sometimes centimeters. Typically, straight rulers are not longer than 144 inches in length. There are folding rulers that are made of wood and have hinged sections. Rulers often are on levels so that you can create a level surface while measuring the length of the surface at the same time.

Micrometer

A micrometer measures length within .001 of an inch or .025 of a millimeter. It is a calibration measuring tool. As of 2010, micrometers can cost from $500 to $1500 depending on the the length they are able to measure. They also can measure depth and diameter.

Electronic Linear Scale

A electronic linear scale is used for measuring the length of a surface. It uses an induced current position transducer that has a slider mounted to the elongated beam. The slider is mounted on a device--for example a tool that is being used--and the beam is mounted on the device. The two members move relative to each other and determine the distance between the two. These are used when precision measurements are needed. The precision is within plus or minus .002 inches to plus or minus .008 inches.

References

• All Measure: Rules and Tapes
• Engineer Supply: Measuring Rod Rulers

Resources

• Patent Storm: Electronic Linear Scale
• Tresna Instrument: Types of Micrometers