Portable hardness meter measurement is not accurate

(1) The diamond indenter does not meet the technical requirements or wears out after using for a period of time. If the operator cannot judge the quality of the diamond, it can be verified by the metrology and testing institution. (2) Steel ball head strength and hardness is not enough, easy to produce deformation. The steel ball is flattened and deformed elliptically. When the short axis is perpendicular to the surface of the parts, the indentation is shallow and the value is high. When the long axis is perpendicular to the surface of the parts, the indentation deepens, the indication value decreases, and the ball tolerance is 0.002mm smaller.

The following hardness tester manufacturer xiaobian to talk about portable hardness tester measurement is not allowed

I. Load:

(1) The initial load, there is friction between the spring and the spindle, the lever and the dial indicator, resulting in the increase or decrease of 100N. Adjust screw loose, adjust move, push rod position is improper.

(2) There are differences in the starting line, resulting in incorrect initial load. If the initial load is not correct, should adjust the spring, spindle, lever, dial indicator, etc. After the position of the adjusting block is moved properly, tighten the adjusting screw and the push rod at the same time. The allowance of initial load should be less than ±2%.

Two, the impact of portable hardness tester pressure head:

(1) The diamond indenter does not meet the technical requirements or is worn after a period of use. If the operator cannot judge the quality of the diamond, it can be verified by the metrological testing institution.

(2) Steel ball head strength and hardness is not enough, easy to produce deformation. The steel ball is flattened and deformed elliptically. When the short axis is perpendicular to the surface of the parts, the indentation is shallow and the value is high. When the long axis is perpendicular to the surface of the parts, the indentation deepens, the indication value decreases, and the ball tolerance is 0.002mm smaller.

Three, the influence of the surrounding environment.

Portable hardness tester used in factory production is often affected by vibration of the surrounding environment, resulting in loose instrument structure and unstable value. Portable hardness tester should be installed in no vibration or far from the source of the place.

Four, portable hardness tester placement is not right.

(1) portable hardness tester is not in a horizontal position, when testing hardness, its value is low. Measure levelness with a level, then level with a portable durometer.

(2) parts of a test part of the surface and the table contact is not good, or the support point is not stable, will produce sliding, rolling, warping and other phenomena. This not only makes the results inaccurate, but also damages the instrument. A suitable worktable shall be designed according to the geometry of the parts.

Five, main load:

(1) the lever proportion is not correct, and the balance weight of the boom and weight has error; Deflection of spindles, levers and weights can cause errors in the main load. The leverage ratio is wrong and should be adjusted. Knife-edge wear should be repaired or replaced, and spindle deformation should be straightened.

(2) spindle, lever and weight deflection should be adjusted. Tolerance of main load of all scales is less than ±0.5%.