Products that use sensors with or without actuators to measure and optionally control one or more parameters of fluids (liquids and/or gases). The measured parameters may include without limitation volumetric flow, mass flow, density, concentration, viscosity, dielectric constant, refractive index, pH, color, dissolved oxygen, level, energy content, heat capacity, content, composition, BRIX, API, temperature, and other specific quality indicators. The measured parameters may be used to monitor with optional control the quality and/or quantity of the fluids, devices that use the fluids, or fluid consumers. The products may have optional control features to further optimize the efficiency of a machine using the fluids (user) or fluid manufacturer (the fluid producer), manufacturers of other products (general manufacturers), mixing, and/or monitoring the authenticity of fluids (custody transfer or quality control), as well as other applications. These products can be used in a variety of applications and fields