Flow measurement hits home

The conception, design fabrication, and test of a demonstrator of a low-cost flowmeter for washing machines and other home appliances has been described in this article. Mechanical, thermal, and electric simulations were required to set the parameters of the system, and links between thermal and electrical domains were established through SPICE-equivalent circuits. Closed-loop measurements using a electro-thermal sigma-delta converter improve the linearity compared with open-loop differential voltage measurements. A novel design of the packaging may lead to an inexpensive unit price when commercially produced.