A force gauge (also known as force gage) is a small measuring instrument utilized universally across all industries to measure force during a push or pull test. Its uses exist in production, research and development and quality laboratory environments.
Both digital and mechanical force gages are used widely. But the digital ones are replacing gradually their mechanical force counterparts in the field. A digital force gauge is basically a handheld instrument containing electronics, integral load cell and display.
The load cell (or force sensor) is the heart of any type of digital gauge. It’s basically a spring which flexes as the force is exerted on it. When the spring flexes, strain gauges measure the strain as well as output a voltage. If the force is greater, the strain is equally going to be greater, resulting into greater voltage output. Through microprocessor and electronics, the voltage is converted into force value which is displayed on the instrument.
As opposed to other kinds of measuring instruments like coating thickness gauges and tachometers, the bodies of these instruments may witness a major amount of force-normally up to 1,000 pounds. Therefore, their housings are typically constructed using rugged materials.
They are available in different force capacities, reflecting the great amount of various products which require testing. Test units are most generally newtons, kilograms and pounds. Different test stands, fixtures and grips are available for use with the instruments that widely vary, depending on the sample being tested.
Of major interest in majority of applications is the peak force (or maximum observed force) during the test process. This metric is normally used to determine if a part is acceptable or not. For example, an acceptable bag of potato chips may open at between two and three pounds of force, while an acceptable door latch on a vehicle might require between six and eight pounds of force to open.
The gauges are compact though capable instruments which may be utilized for different push and pull testing requirements.
How to Use a Force Gauge
Proper use of these instruments is quite simple. However, failure to follow some basic instructions may result in inconsistent or incorrect results and damage to the instrument.
In majority of testing of manufactured components, it’s vital that the load is axially applied with respect to the gauge. If not, it’s possible that damage may occur to load cell, or the displayed force reading may be skewed due to the angle of measurement.
Another important point to take into account is that the instrument shouldn’t be employed in measuring impact or shock loads. An unexpected force buildup might not very accurately be measured. These instruments are most effectual at longer duration tests.
Consistent speed is a significant, though normally overlooked, factor in force measurement. Due to this fact, handheld testing isn’t advised for majority of applications. A sample might require, depending on the test speed, a lesser or greater force to achieve the objective of the test. The speed should be consistent so that the subsequent tests may be compared according to similar parameters. Various standards specifying test speeds have been published.
A manual test stand, specifically hand wheel types, or motorized test stand is useful in assisting to achieve consistency of speed. It correctly aligns also the force gauge and provides normally ample fixture-mounting holes.
Interpreting the Results
As previously discussed, the peak force normally is considered the most significant determinant in force test. Typical for production environments, in such applications, some peak forces from a batch might be collected and evaluated. It’s common to set lower and upper control limits and get statistics from these data.
A number of other applications need more than just the peak. Often, laboratory testing requires force profile to be recorded and utilized to analyze scientifically the sample’s behavior. This is quite common in testing of materials, for instance, the testing of plastics and metals- and in testing also assemblies like sealed pouches, push buttons and bottle caps.
A force gauge is a capable instrument having different applications. It may be used for different simple peak force measurement. However, it may be used also in complicated test applications that require scientific assessment of a sample. With right use, it may yield a wealth of useful information with which quality professionals may quantify the finished products’ quality.