Optical comparators are essential tools when it comes to measuring various dimensions of a part. Optical comparators are widely used in manufacturing plants and machining shops for quality control. They work by projecting (and magnifying) an image of the part being assessed on to a screen. Once the image is on the screen, several approaches can be used to measure different parameters of the object. Optical comparators are particularly favored by machinists because they are non-contact measuring instruments and therefore tend to be very accurate. They also are able to measure dimensions of very small parts that would be very difficult to measure in any other way. Optical comparators are easy to use and machine operators with no or very little experience can easily be trained on how to use them in very little time. Finally, they are compact and are suitable for environments where space comes at a premium.
How Optical Comparators Work
Once the image has been projected on to the screen, there are various approaches that can be used to measure the dimensions of a part. The most basic of them is to superimpose the image on preset calibrations on the screen so that at a glance, the machine operator can tell if there is variance between the two and if it warrants modification of the part. Another way in which measurements can be taken is by aligning various points of the image to the centerline of the screen and then moving the stage on which the part lies. The optical comparator is then able to measure the distance the stage moves to reach each of those points, thus give an accurate reading of the dimensions of the part. Optical comparators can measure a variety of dimensions including length, width, diameter, radius and many more.
Measuring Radius with an Optical Comparator
The radius of an object can be measured easily with an optical comparator. One starts by securing the object to be measured firmly in place on the stage. This can be done using clamps which help secure it and prevent movement that can affect the readings of the optical comparator. Once that is done, a silhouette of the object will be projected on to the screen through the lens on the machine. The next step involves setting the optical comparator to measure the radius and taking the readings from the display attached to the machine.
What to Lookout For
When using an optical comparator to measure the radius, one must be careful to ensure that as many parts of the object as possible are projected into the screen to improve the accuracy of the reading. If you are looking to get an optical comparator, look out for newer models. Modern optical comparators are making it easier for machine operators to measure dimensions such as radius. There are optical comparators that come with touchscreen capabilities, allowing the machine operator to adjust the image on the screen. New digital optical comparators can provide accurate readings without the need to adjust the screen or move the stage.