Level measurement

68 Continuous level measurement in liquids

4. Instrument selection within the measuring principle

Guided radar

Required application data Level measurement • Pressure and temperature • Dielectric constant (DC) of the medium • Required material compatibility • Nozzle diameter: DN, PN, nozzle height • Measuring range Additional for interface measurement • Dielectric constant (DC) of both liquids Application limits for guided level radar • Temperature up to -196°C/-321°F • Temperature up to +450°C/+842°F • Pressure up to +400bar/+5,800psi • (longer upon request) • • • interface measurement (upon request)

Dielectric constant (DC) The reflection properties of a medium are determined by the dielectric constant (DC). The following table shows the allocation of different DC values to media groups. If the dielectric constant of a medium is not known, we recommend to use a DC value of 1.9 for sizing in order to maintain a safe measurement.

C

Media group

DC

Typical liquids

FMP50

FMP51

• Liquified gases, 2 , CO 2 • • Solvent • Frigen / Freon • Palm oil

6m/20ft not with rope

1

1.4 to 1.6

4m/13ft

25 to 30m/ 82 to 98ft

2

1.6 to 1.9

12m/39ft

• Mineral oils • Fuel

30 to 45m/ 98 to 148ft

3

1.9 to 2.5

12m/39ft

• Benzene, styrene, toluol • Furan • Naphthalene • Chlorobenzene, chloroform • Nitrocellulose lacquer • Isocyan, aniline

4

2.5 to 4

12m/39ft

45m/148ft

5

4 to 7

12m/39ft

45m/148ft

• Aqueous solutions • Alcohols • Acids, lyes

6

>7

12m/39ft

45m/148ft