Benchtop or floor model. Choosing between benchtop and floor-model comparators depends on the size and weight of the parts to be measured, floor space, required screen size, and cost. Benchtop models are smaller, lighter, and have lower load-carrying capacities and measuring ranges. They are often used to measure small, lightweight parts such as plastic moldings, stampings, and lathe work. Floor models offer heavy-duty load capacities and larger travel, and are typically used to measure large machined castings, dies, and heavy tooling.
Optics are the heart of any comparator.
Because it is the image that is measured, not the part itself. To ensure that the image is accurate, optical quality in design and manufacture is critical. Several types of optics are offered. A projection lens magnifies the object, and the image is directed to the screen by one or two mirrors. If one mirror is used, the image is inverted and reversed.