Question

Explain the system of the micrometer screw.

Answer 1

Explanation: Micrometer Screw gauge is a form of Callipers used for measuring small dimensions .

A screw gauge consists of a "U" shaped metallic structure, which is attached to a hollow Cylindrical tube on one end . The Hollow tube has a uniformly threaded nut inside it. A long stud with a plane face is fitted into this nut.

Exactly on the opposite side of this nut and on the other end of the U shaped frame , a smaller stud with a plane face is also attached . Faces of both the studs are exactly parallal to each other. This U shaped metallic structure is known as the anvil and the longer one is known as spindle. The anvil is fixed part of the device , whereas the spindle moves as and when the head is moved .The frame carries both the anvil and barrel, and is also heavier than the rest of the parts. The object to be measured is held between the anvil and the spindle . The Barrel or Sleeves is connects the frame to cylindrical tube . It is non movable part of screw gauge and has a scale of the device . Moreover, it also carries the most important part of the micrometer the screw . The screw is the heart of the micrometer and is located inside the barrel . The screw converts small dimensions into measurable distance using a scale .

There is one more part called the ratchet which is provided at the end of the tube. The ratchet is kind of limiting device which applies a pressure by slipping at a predetermined torque and thus prevents the spindle from moving further.