The optical measurement uses optical sensors to collect measurements. There are advantages and disadvantages that must be weighed when using instruments capable of optical measurement. Many different types of systems are available, including fully automatic systems, video measurement system, as well as systems that allow more manual control for precise measurements. High-end systems can be quite expensive and are found in laboratories and material testing facilities where accurate measurements are critically important.
One of the main benefits of optical metrology is that it is non-invasive. Beyond the phase contact of the optical measuring vision system, no contact is required. The probe does not touch the object being measured and the instrument does not rely on destructive measurement techniques. For many applications, there is a desire to keep the objects being measured intact throughout the process, and subsequently, optical measurement can be highly attractive.
This technique can also be very accurate. The optical sensor is highly sensitive and can detect subtle gradations and other differences that may not be visible to someone using probes or manual measurement techniques.