Embedded viscosity measurement system using a vibrating-wire sensor

This paper presents an embedded measurement system capable of performing viscosity measurements using a vibrating wire sensor. The system is based on a DSP (digital signal processor), which controls the hardware in the system and is responsible for obtaining the viscosity estimation. The user interfaces with the system through a keypad and a LCD, but has the option to control it through a PC with a USB connection. The viscosity of the fluid in which the sensor is immersed is estimated based on the impedance frequency response of the sensor when an AC current is applied to the sensor´s terminals. The paper presents viscosity measurements obtained with several sample fluids and the results are compared with viscosity values available in the literature.