转速计，又名转速表、转速仪，是机械行业必备的仪器之一，用来测定电机的转速、线速度或频率。常用于电机、电扇、造纸、塑料、化纤、纺织、汽车、飞机、轮船等制造业。 大多常用的为手持离心式转速计。

转速计，又名转速表、转速仪，是机械行业必备的仪器之一，用来测定电机的转速、线速度或频率。常用于电机、电扇、造纸、塑料、化纤、纺织、汽车、飞机、轮船等制造业。 大多常用的为手持离心式转速计。美国Checkline旗下的转速计一般为数字式，有接触式和非接触式两种测量。非接触式采用光电器件测量，无连接轴，对被测件无任何影响，提高测量精度。

例如Checkline DT-2100型是一款接触式&非接触式转速计，集成了数据采集，USB输出和可编程拓展三大功能。

The Check-Line DT-2100 is an advanced combination contact / non-contact hand-held tachometer. The DT-2100 features data-logging, USB output and a programmable scaling feature to offset RPM according to application variables. It features a backlit LED Display with upper/lower limit icons and a unique X-Y Graphic mode. Additional display modes unique to the DT-2100 is the "Needle Sweep" and Bar Graph" offers the user a choice of how to view the data. The display can also be inverted to optimize the viewing angle.

In non-contact mode the tachometer measures RPM up to 99,999 RPM at distances up to 13 feet or 500 cm. The DT-2100 can also measure contact RPM, surface speed, or length using the supplied screw-on adapter.

Data logging can be set for single point or continuous logging. Single data points as well as statistics (Max, Min, Average) can be stored in the built-in memory and recalled to the display. Often users need to adjust machinery during testing, with the DT-2100 you can mount it on a tripod, select continuous logging and adjust machinery as necessary. After the test, you can easily review the data on the DT-2100's display or download to a computer using the optional PC Software.

The Checkline DT-2100 is supplied as a complete kit with 2 cone tip adapters, funnel tip adapter, shaft extension, 6 inch circumference surface speed wheel, reflective tape, 2 AA batteries ... all supplied in a foam-fitted carrying case. An NIST-Traceable Calibration Certification is optionally available.