Level Measurement · Glossary

What is a Radar Level Transmitter?

non contact microwaveLevel Measurement

A radar level transmitter measures level from the travel time of microwaves reflected from the liquid surface.

Radar Level Transmitter Explained

The antenna sends microwaves down to the surface and receives the echo. Pulse radars time the echo; FMCW radars sweep frequency and calculate distance from the frequency difference.

Radar is not affected by temperature, pressure or gas composition in most service. Higher frequencies such as 80 GHz give a narrow beam that avoids internal obstructions.

Radar Level Transmitter Formula

d = c × t ÷ 2 and L = H_ref − d

c	speed of light, 299,792,458 m/s
t	round trip time
H_ref	reference height to tank bottom

Example: A 20 ns round trip is d ≈ 3.0 m.

Radar Level Transmitter: Typical Values

Common frequencies	about 6, 26 and 80 GHz
Water εr	about 80, strong echo
Hydrocarbons εr	about 2, weaker echo

Calculators for Radar Level Transmitter

CalculatorRadar Level CalculatorFree online calculator with formula and worked example.CalculatorRadar Level Dielectric CalculatorFree online calculator with formula and worked example.CalculatorTank Ullage CalculatorFree online calculator with formula and worked example.

Free Downloads

Free downloadRadar Level Transmitter Commissioning ProcedureFree step by step procedure, Word and PDF.Free downloadLevel Transmitter Datasheet Template in ExcelFree download in Excel and PDF.

Frequently Asked Questions

What is a Radar Level Transmitter?

A radar level transmitter measures level from the travel time of microwaves reflected from the liquid surface.

Does foam affect radar?

Light foam can absorb or scatter the signal. Heavy or conductive foam may give an echo from the foam top.

Why mount away from the inlet?

Falling product creates false echoes and a turbulent surface.

Learn more on the blog

Guided wave radar vs non contact radar

A practical guide on instrumentationblog.in with more detail on radar level transmitter and how it is applied on real plants.

Read Full Article

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