在生产和研究工作中,常用硬度计直接测定砂型表面的硬度,以表示砂型的表面紧实程度。但过去通用的湿型硬度计在生产上经常需要测定的范围内(“容重”δ为1.55～1.65克/厘米~3),却不够灵敏,硬度值读数变化很小。在高压、射压等新型造型方法发展的今天,对高紧实度砂型(8>1.70克/厘米~3)测定时, In the production and research work, the commonly used hardness tester directly determines the hardness of the surface of the sand mold to indicate the degree of surface compaction of the sand mold. However, in the past, the commonly used wet type durometer has been often measured in the production range (“bulk density” δ is 1.55-1.65 g / cm 3), but it is not sensitive enough, and the hardness value changes little. In the development of new modeling methods such as high pressure and shot press, when the determination of high compacted sand (8> 1.70 g / cm ~ 3)