莱州市试验机金刚石工具厂

　　洛氏硬度计硬度值调整注意事项

　　硬度计的种类有洛氏硬度计 、显微硬度计、布氏硬度计、维氏硬度计、里氏硬度计、邵氏硬度计、肖氏硬度计、巴氏硬度计、水果硬度计、水泥硬度计等 。

　　现列举如下：

　　1、硬度计本身会产生两种误差：一是硬度值误差;二是硬度值重复性误差。对第一种误差，在测量前需用标准块对硬度计进行校准。对洛氏硬度计校正结果，差值在±2之内合格。在硬度值调整时，首先调整高值和底值，新机器一般可以调整到±0.5-1之内。对第二种误差，就要全面检查仪器的各个环节，如仪器是否水平、砝码位置是否正确等。

　　2、在更换或砧座时，注意接近部位要擦干净。换好后，要用一定硬度的钢样测试几次，直到连续两次所得硬度值相同为止。目的是使压头或砧座与试验机接近部分压紧，接近良好，以免影响试验结果的准确性。

　　3、 硬度计 调整后，开始测量硬度时，第一个测试点不用。因怕试样与砧座接近不好，测得的值不准确。特第一点测试完，硬度计处于正常运行机制状态后再对试样进行正式测试，记录测得的硬度值。

　　4、在试件允许的情况下，一般选不同部位至少测试三个硬度值，取平均值，取平均值作为试件的硬度值。

　　5、对形状复杂的试件要采用相应形状的垫块，固定后方可测试。对圆试件一般要放在V形槽中测试。

　　6、加载前要检查加载手柄是否放在卸载位，加载时动作要轻稳，不要用力太猛。加载完毕加载手柄应放在卸载位置，以免仪器长期处于负荷状态，发生塑性变形，影响测量精确度

Rockwell hardness tester hardness value adjustment matters needing attention

The types of hardness tester are Rockwell hardness tester, micro hardness tester, Brinell hardness tester, Vickers hardness tester, Leinell hardness tester, Shore hardness tester, Shore hardness tester, Barinell hardness tester, fruit hardness tester, cement hardness tester and so on.

The list is as follows:

1, hardness tester itself will produce two kinds of error: one is the hardness value error; Second, repeatability error of hardness value. For the first error, the durometer should be calibrated with a standard block prior to measurement. The calibration result of Rockwell hardness tester is qualified within ±2. When the hardness value is adjusted, first adjust the high value and the bottom value, the new machine can be adjusted to ±0.5-1. For the second error, it is necessary to check all aspects of the instrument, such as whether the instrument level, weight position is correct.

2, in the replacement or anvil, pay attention to the close part to wipe clean. After the replacement, the steel sample of a certain hardness should be tested several times until the hardness value is the same for two consecutive times. The purpose is to make the head or anvil seat and testing machine close to part of the compression, close to good, so as not to affect the accuracy of the test results.

3. After the hardness tester is adjusted, the first test point is not used when the hardness is measured. For fear of specimen and anvil close to bad, measured value is not accurate. After the test of the first point, the hardness tester is in the state of normal operation mechanism, and then the specimen is formally tested, and the hardness value measured is recorded.

4. Under the condition that the specimen is allowed, different parts are generally selected to test at least three hardness values, and the average value is taken as the hardness value of the specimen.

5, the shape of the complex specimen to use the corresponding shape of the pad block, fixed rear can be tested. The circular specimen is generally tested in a V-shaped groove.

6, before loading to check whether the loading handle is placed in the unloading position, the loading action should be light and steady, do not force too hard. After loading, the loading handle should be placed in the unloading position, so as to avoid the plastic deformation of the instrument under load for a long time, which will affect the measurement accuracy