Optical Tachometer for USP and ASTM Validation

Determine the real rotational speed of your baskets and paddles

Accurate stirring speeds of baskets and paddles are essential for good dissolution. The USP states that the stirring speed should be ±4rpm. In fact, this is a wide margin and typically most modern dissolution testers should be able to operate with a tolerance of ±0.1rpm.

The most accurate form of testing rotational speed is with an Optical Tachometer. A reflective sticker is placed on the shaft or shaft drive. The optical tachometer shines an Infrared light on to the shaft at this point. The reflection is then measured at every rotation, giving an accurate reading of the rotational speed.