Abstract: An apparatus for sensing liquid flow rate comprises a conduit for conducting a flow of liquid through it and a flow sensor. The flow sensor includes a fixed portion attached to a sidewall of the conduit. The fixed portion has a pair of stationary electrodes positioned in spaced apart relation and adapted to contact the liquid conducted through the conduit. The flow sensor further includes a cartridge portion adapted for removable engagement with the fixed portion. The cartridge portion has sensor terminals adapted to electrically engage the stationary electrodes. In addition, the flow sensor includes an electromagnetic coil operative to generate a magnetic field within the fluid flow.