Pin Brinell type Brinell PHB-150 is a classic portable Pin type Brinell hardness tester, relying on a fixed test force applied to the shear pin, when the shear pin fracture we get the indentation in the workpiece. After measuring the indentation diameter and then check the conversion table to get the Brinell hardness value. In the practical application will also be involved in the calibration of PHB-150. PHB-750 portable Brinell hardness tester is developed by our company according to the Brinell hardness similarity principle of 750kg test force with 5mm ball indenter test condition.It has been recognized and used by more and more customers, about the instrument calibration problem is also achieved by indirect calibration method
I try to explain clearly the calibration problem of PHB-150 and PHB-750 as follows:
1.it is hard for us to make direct calibration of PHB-150 and PHB-750.You know that in ISO standard, for Brinell method, there are three key points: A: 10mm ball; B: 3000kg test fore; C: keep 10-15 seconds. And according to Brinell Similarity principle, my PHB-150 ( 7.26MM ball and 1580kg test fore) and PHB-750( 5MM ball and 750kg test fore) , they are equal to normal condition of 10mm ball and 3000kg test fore). But they have different test fore curve, so it is difficult to calibrate it test force of PHB-150 and PHB-750.
2. You can use indirect calibration method to do calibration of PHB-150 and PHB-750. That is use your standard test block to calibrate if these tester is accurate or not.