Depth gauge
This is a specialized instrument which measures steps and depth of work by hand.
Setting “0” by sticking bottom face of base to measuring datum ( zero point) and rotating outer frame. ( Outer frame is fixed by clump at that time )
Then, it reads with short and long hands how gauge head juts out from that position.
There are 2 types of analogue and digital and they correspond to usage of shape of gauge head and basic size. There are such standard models like 10mm, 20m, 30mm, and it can comparatively measure depth of 220mm to 240mm by connecting leg.
The photo shows measuring depth of work of which center is hollowed. Parts and products can be measured with stuck to the bottom of base which can not be held by hand. The photo indicates 2.03mm.
