轉速計，又名轉速表、轉速儀，是機械行業的儀器之一，用來測定電機的轉速、線速度或頻率。常用于電機、電扇、造紙、塑料、化纖、紡織、汽車、飛機、輪船等制造業。 大多常用的為手持離心式轉速計。美國Checkline旗下的轉速計一般為數字式，有接觸式和非接觸式兩種測量。非接觸式采用光電器件測量，無連接軸，對被測件無任何影響，提高測量精度。

例如Checkline PLT-5000型是一款小型轉速計，精準測量轉速和表面速度。適用于各種機械和材料處理應用。

PLT-5000運用：

The PLT-5000Pocket Laser Tachometer accurately measures RPM and Surface speed using contact or non-contact measurement techniques. This battery-powered unit is extremely compact for convenient portable use and is supplied in a rugged and attractive plastic housing that is ergonomically designed for optimum comfort.

CHECK-LINE小型激光轉速計PLT-5000，擁有非接觸式和接觸式兩種測量技術，可測量轉速和表速。機身小巧，攜帶方便，內置電池。塑料材質外殼結實美觀，增加產品使用舒適感。

When measuring RPM in the non-contact measuring mode, the PLT-5000 emits a precision laser beam that is aimed at a small piece of reflective tape, which is affixed to the rotating target.

The PLT-5000 is extremely easy to operate and quickly converts from non-contact operation to contact operation by screwing the contact adapter in place. In addition to RPM's, a wide variety of engineering units for surface speed and length are user-selected via the front panel buttons. Units include; feet per minute, meters/min, yards per minute, inches per minute and more.

A built-in memory stores up to 10 measurements plus minimum, maximum, average and last.

在非接觸式模式下，PLT-5000通過發射一條精準的激光束到被測件的反光板上來測量轉速。PLT-5000操作起來非常簡單，只需要將轉換頭擰到適當位置就可以快速的進行接觸式和非接觸式兩種模式的轉換。還可以通過前面板上的按鈕來選擇自己想要的測量三個種類，轉速，表速和長度。測量單位包括：英尺/分，米/分，碼/分，英寸/分等。