# Linear measurements page

Suppose there were no units for measuring length. Hypothesize how lengths might be described. Signal conditioning for strain gages 1. In mechanical testing and measurement, you need to understand how an object reacts to various forces. The amount of deformation a material experiences due to an applied force is called strain. Strain is defined as the ratio of the change in length of a material to the original, unaffected length, Linear measurements page shown in Figure 1.

Strain can be positive tensiledue to elongation, or negative compressivedue to contraction. When a material is compressed in one direction, the tendency to expand in the other two directions perpendicular to this force is known as the Poisson effect.

Although dimensionless, strain is sometimes expressed in units such as in. Strain is the ratio of the change in length of a material to the original, unaffected length. The four different types of strain are axial, bending, shear, and torsional. Axial and bending strain are the most common see Figure 2.

Axial strain measures how a material stretches or compresses as a result of a linear force in the horizontal direction. Bending strain measures a stretch on one side of a material and the contraction on the opposite side due to the linear force applied in the vertical direction.

Shear strain measures the amount of deformation that occurs from a linear force with components in both the horizontal and vertical directions. Torsional strain measures a circular force with components in both the vertical and horizontal directions.

Axial strain measures how a material stretches or pulls apart. Bending strain measures a stretch on one side and a contraction on the other side. Back to Top 2. How do you measure strain? You can measure strain using several methods, but the most common is with a strain gage. The most widely used strain gage is the bonded metallic strain gage. The metallic strain gage consists of a very fine wire or, more commonly, metallic foil arranged in a grid pattern.

The grid pattern maximizes the amount of metallic wire or foil subject to strain in the parallel direction. The grid is bonded to a thin backing called the carrier, which is attached directly to the test specimen.

Therefore, the strain experienced by the test specimen is transferred directly to the strain gage, which responds with a linear change in electrical resistance. The electrical resistance of metallic grid changes in proportion to the amount of strain experienced by the test specimen.

A fundamental parameter of the strain gage is its sensitivity to strain, expressed quantitatively as the gage factor GF.

## Amplifiers

GF is the ratio of the fractional change in electrical resistance to the fractional change in length, or strain: The GF for metallic strain gages is usually around 2. You can obtain the actual GF of a particular strain gage from the sensor vendor or sensor documentation.

In practice, strain measurements rarely involve quantities larger than a few millistrain e x This is particularly important for accurate gap and flush measurements. The system is flexible. Measurement routines are developed using the LGWorks software.

Measurement locations for each vehicle are taught to the robot. Implementation is completed in a matter of days, not weeks. LMI Corporation provides a wide variety of dimensional gauging.

linear body measurements had higher values (Pmeasurements of girth, width and depth, which did not differ significantly between breeds.

Mature goats had. Measure and document wounds in centimeters and record measurements in the order of length, width, and depth; for example, “4 cm × 2 cm × cm.” Use the . IED Activity Making Linear Measurements– Page 3 b.

Measure the location and size of the opening on the top of the part. Record your measurements on the top view below to the appropriate number of significant digits.

inches (2 inches) inches inches (1 5/8 inches). Metric measuring units worksheets. In Book 1, students learn how a linear measurement system is developed and then do activities related to measuring length.

Book 2 focuses on length, perimeter, and area measures. In Book 3, the concept of area is further developed, and students are introduced to volume. Book 4 covers a variety of topics. Measurement Index Measurement is finding a number that shows the size or amount of something.

There are two main "Systems of Measurement": Metric and US Standard.

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