硬度计是测量物体硬度的仪器，表示材料抵抗硬物体压入其表面的能力。它是金属材料的重要性能指标之一。一般硬度越高，耐磨性越好。根据所测硬度单位：洛氏硬度计、维氏硬度计、显微硬度计、布氏硬度计、邵氏硬度计、巴氏硬度计、里氏硬度计、韦氏硬度计、肖氏硬度计、布洛维硬度。根据使用方式：便携式硬度计、台式硬度计。

进口硬度计，美国Check-Line RX-2100，快速测量汽车、赛车轮胎的硬度。

The Checkline RX-2100 Tire Durometer allows racers to quickly and accurately make checks of tire hardness. Unlike other "racing durometers" (which are just relative hardness gauges), the RX-2100 is calibrated to the ASTM D-2240 standard for durometer hardness and is NIST-Traceable. Thus, the RX-2100 allows comparison with the factory tire specifications.

The Check-Line RX-2100 is a handheld gauge weighing only 4.2 oz. The indicator case, bezel, and barrel are all billet machined aluminum. The gauge is furnished with a carrying case and a one year warranty.