Flow Instrument Simulator – Interactive Flow Measurement

October 26, 2026 4instrumentation20

How Flow Transmitters Measure Flow

There is no single way to measure flow. Some meters measure a pressure drop, some spin or shake, some use magnets, sound, heat or radar. Pick a flow transmitter, change the flow, then change the fluid and the installation to find out where each type works well and where it fails.

From flow to 4-20 mA (signal chain)

Sensor signal, conditioning electronics, ADC, microprocessor (linearises, corrects and converts to flow), then the 4-20 mA output. If there is no usable signal the transmitter goes to a fail-safe 3.6 mA.

How it works

About this flow meter type

What it measures
Typical accuracy
Best for
Weak point
Straight pipe needed upstream
Response time constant

1Choose a flow meter type

2Change the flow

Transmitter range

Flowm3/h

The pipe is 100 mm (DN100). 100 m3/h in this pipe is a velocity of about 3.5 m/s.

3Fluid and installation

Fluid

DP primary element

Straight pipe before meter

Air bubbles in the liquid

Density compensation ON (DP type)

Pipe length is given in pipe diameters (D). Bends and valves upstream disturb the flow profile, which spoils some meters. The fluid decides which meters can work at all.

Transmitter readings

True flow
Velocity and Reynolds number
Sensor raw signal
Digital value (16-bit)
Flow read by transmitter
Measurement error
Output (% of span) and current
Suitability for this fluid

Response to a flow change

grey dashed = true flow, blue = what the transmitter reads. Last 60 s.

Sensor signal vs flow

x: flow (% of range), y: raw sensor signal (% of its full-scale change). Orange dashed = a perfect straight line. A curved line (DP: square law, radar: level to the 2/3 power, thermal: square root) must be corrected by the microprocessor.

Compare all flow meter types

Fluid columns: \u25CF works well, \u25B2 poor or limited, \u2715 does not work.

Explore an interactive Flow Instrument Simulator to understand how industrial flow meters measure liquid and gas flow. Compare different technologies, including differential pressure, rotameter, turbine, positive displacement, vortex, electromagnetic, ultrasonic, Coriolis, thermal mass, and open-channel flow measurement.

Adjust flow rate, fluid type, straight-pipe length, and air bubbles to observe changes in sensor signals, measurement accuracy, and transmitter output. Learn how flow velocity, Reynolds number, density, viscosity, and fluid conductivity affect measurement performance.

This simulator is ideal for instrumentation engineers, technicians, and students learning industrial flow measurement and DCS applications.