Optical measurement is a measurement technique that relies on the use of optical sensors to collect measurements. There are advantages and disadvantages that must be weighed when using devices capable of optical measurement. Several different types of systems are available, including fully automated ones, as well as systems that allow for more manual control for precision measurements. High end systems can be quite costly and are found in labs and materials testing facilities where exact measurements are critically important.
One advantage of optical measurement is that it is noninvasive. No contact is required, beyond contact with the stage of an optical measuring device. Probes do not touch the object being measured and the device does not rely on destructive measurement techniques. For many applications, there is a desire to keep items being measured intact throughout the process, and subsequently, optical measurement can be highly appealing.
This technique can also be very precise. The optical sensor is highly sensitive and can detect subtle gradations and other differences that might not be visible to someone using probes or manual measurement techniques. This allows for very accurate measurements. There are many settings where they can be important, like machining precision parts that have very low tolerances and must be produced with as few errors as possible. Optical measurement is also very fast once an item has been set up properly, with the device capable of taking multiple measurements at once.
The primary disadvantage to optical measurement is that automated systems are not necessarily able to correct for errors that humans would be able to address. For example, if a flat part is being measured and there is a small burr along one side, the machine will read the burr into the measurement, while a person would note the burr and compensate during the measurement process. Computed numerically controlled (CNC) systems like those used for optical measurement in settings like quality control can be very adaptable, but they are usually not capable of making intuitive leaps like humans are.
The cost of optical measurement systems varies and they are designed for different uses. Companies that manufacture such systems can provide information about the applications their products are most suited for, as well as offering information about warranties, performance, and other features that might be important to prospective buyers. Many companies also allow people to interact with their equipment before sales are finalized. This gives people a chance to practice and test out new equipment.