In mandrels with taper shanks there deflection should be less than 0.65 µm, for those having working length of 75 mm and 5.8 µm for those having working length of 505 mm.
The caliper gauges are similar to gap gauges with threads provided on anvils. The front anvils with full thread form acts as GO gauge, to check the threads below the size limit.
The Projection comparator is a measuring instrument. It is used for measuring the part of the shadow being on a screen, where it is a compared to a master drawing. The projection comparator method is suitable for complicated type shaped parts.
A pneumatic comparator are utilizes a pneumatic circuit to measure dimensions individually or in combination. Basically, comparators measures size by variation of flow or variations of pressure in its pneumatic circuit.
The electrical comparators are depends upon the operation on an A.C Wheatstone bridge circuit with a galvanometer.
In mechanical optical comparators small displacements of the measuring plunger are amplified starting by a system consisting of pivoted levers.
Mikrokator type mechanical comparator is a mechanical comparator used for obtaining mechanical magnification. It works on the principle of a button spinning on a loop of a string. The mikrokator comparator consists of a twisted thin metal strips to convert plunger small linear movements into pointers large circular movements.
The vertical beam is mounted on the flat steel springs it is connected to the fixed members, which is turning are screwed to a back plate.
The reed type mechanical comparator is a device used for measuring the objects dimensions. The reed type mechanism is a frictionless device for magnifying small motions of the spindle which is connected horizontal to the fixed block.
These are usually robust, compact and easy to handle. These do not require any external supply such as electricity or air and as such the variations in outside supplies which are not affect the accuracy.