Practical engineering guide

Preparing a flow measurement specification

A suitable flowmeter depends on the medium, operating conditions and measurement purpose. The same pipe size may require different equipment for process indication, batching or accurate consumption monitoring.

Start with the purpose and operating range

Distinguish volumetric flow from mass flow. Specify minimum, normal and maximum rates, then describe starts, flushing and batches separately. A pump rating does not necessarily describe conditions at the measurement point. Accuracy requirements must make sense at the actual operating flow; repeatability, response and the use of the result also matter.

Understand the limits of each principle

Electromagnetic meters suit electrically conductive liquids; conductivity and pipe filling conditions depend on the selected instrument. Coriolis measurement gives mass flow directly, but selection must consider pressure loss and behaviour with entrained gas. Clamp-on ultrasonics measure through the pipe wall. Suitability depends on the pipe, acoustic transmission and the condition of the medium.

Define the complete measurement point

Engineering should specify material compatibility, installation, power, signals and checks. One straight-run requirement cannot apply to every technology. An instrument calibration certificate does not replace verification of the installation and its signal path into the control system. Poorly defined conditions can make an otherwise suitable instrument unstable or cause its readings to be interpreted incorrectly.

Expected engineering outputs

Instrument and measurement principle specification.
Installation requirements and associated component list.
Agreed measurement, signal and documentation checks.

Technical sources and further reading

Reviewed on 18 October 2026. Product limits and applicable requirements are confirmed for each specification.

Selection in context

Comparing flow measurement principles

Select the principle against the fluid, actual flow range and installation conditions; the complete measurement point determines the resulting uncertainty.

On a small screen, scroll the table sideways to compare the selection criteria.

Comparing flow measurement principles
Principle or option	Typical application	What to verify when selecting
Electromagnetic flowmeter	Volumetric flow of conductive liquids, such as utility water or conductive process solutions.	Conductivity, a full measuring tube, electrodes and liner, grounding, and manufacturer installation requirements.[1]
Coriolis flowmeter	Mass flow for liquid batching and material balances; gases where supported by the selected design.	Minimum and maximum flow, pressure loss, gas entrainment in liquids, vibration and required measurement response.[2]
Clamp-on ultrasonic	Retrofit or temporary measurement from the outside of existing pipework.	Pipe material, dimensions and lining, acoustic transmission into the fluid, bubbles or particles, and available straight length.[3]
Vortex flowmeter	Steam, gas and liquid flow within an appropriate operating range.	Sufficient flow for vortex shedding, flow profile, vibration and steam condition; density compensation for the required output quantity.[1]
Differential pressure across a primary element	Liquid, gas or steam flow derived from pressure difference across an orifice or another sized primary element.	Element and pipe geometry, density, measuring range, pressure loss, pressure taps and impulse-line arrangement.[4]

Sources for this comparison

Reviewed on 18 October 2026. Selection is confirmed for the specific operating conditions and equipment design.

Before we start

Questions that shape the project.

Can the meter simply match the pipe size?

Not necessarily. Sizing must suit the flow and technology while considering velocity, pressure loss, installation and access. Any reducers or alternative arrangement are defined during engineering.

Does catalogue accuracy guarantee installed accuracy?

Not automatically. The manufacturer states defined conditions. Installation, range, medium and signal processing influence the result, so acceptance criteria must address the actual measurement point.

Your next project

A clear brief.
A practical next step.

Send your drawings, operating parameters or a short description of the change you need. We will review the technical interfaces and propose the next steps towards a quotation, clarifying any missing information with you.

Discuss your requirements ↗Prepare a technical brief →+420 731 771 147 info@emkoproject.cz