The 75-I tachometer is a recorder used for measuring length and various machine rotations, generally suitable for mining drilling depth. It measures and records the length of the cable and the number of coils wound.
This table is a five digit number, with the rotation direction of the shaft being clockwise and counterclockwise, clockwise rotation being increasing, and counterclockwise rotation being decreasing. The highest recorded number is 99999.
The first digit to be rotated is 1/10 of the rotation axis, and the axis can automatically carry after one rotation.

The 75-I rotary length counter is equipped with a reset mechanism. If a certain number of records are recorded, the push handle can be reset to zero, and then the second stage of recording can be made.
Attention should be paid to balance when installing this table, and it should be concentric with the host when in contact, otherwise it may cause the rotation to twist or break, resulting in inaccurate counting or malfunction.
The maximum speed of this table is 350 times per minute. If it is too fast, it may cause damage to the components.
When resetting to zero, the leading digit must be turned within the range of the window cover and cannot be reset during rotation.
The wheel and gear of the 75-I rotary length measuring counter are made of special engineering plastics and should not come into contact with high-temperature flammable gases. The bearing must be regularly oiled.