Density & Viscosity

Density and viscosity are the properties that tell an operator what is flowing, not just how much. Density identifies a product, shows the concentration of a solution or the solids content of a slurry, marks the interface between two products in a pipeline and converts volume to mass for custody transfer. Viscosity governs how a fuel burns, how a lubricant protects, how a polymer processes and how a product will feel to the customer, and it is the first thing that changes when a process drifts.

Both have traditionally been laboratory measurements: a sample drawn, carried, cooled and tested, with the result arriving hours later. The instruments in this category measure them inline and continuously. Coriolis density meters vibrate a tube carrying the process fluid and derive density from its resonant frequency with accuracy to ±0.1 kg/m³, and calculate concentration, °Brix, °API or percent solids from it. Vibrating-fork density meters put the same principle on an insertion probe that mounts directly into a pipe, tank or bypass through one connection, with stems up to four metres for deep vessels. Tuning-fork viscosity meters read both the resonant frequency and the damping of the fork, reporting viscosity and density together with temperature compensation and referral to a standard temperature.

All three families operate at high pressure and temperature, in materials from 316L to tantalum and titanium, and communicate over 4–20 mA HART, Modbus and WirelessHART.

Metron MENA supplies these instruments to oil and gas, petrochemical and chemical plants for blending, interface detection, concentration control, fuel and lubricant monitoring and fiscal measurement, and engineers the installation together with the flow and level instruments in the same process.