VEGA VEGAPULS 62 (≥ 2.0.0 - ≥ 4.0.0) Foundation Fieldbus Approval according to LPR radio standard - Manual (Page 67)

Influence of the superimposed gas and pressure to the accuracy
The propagation speed of the radar impulses in gas or vapour above the medium is reduced by
high pressure. This effect depends on the superimposed gas or vapour and is especially large at
low temperatures.
The following table shows the resulting deviation for some typical gases and vapours. The
specified values refer to the distance. Positive values mean that the measured distance is too
large, negative values that the measured distance is too small.
Gas phase Temperature Pressure
1 bar/
14 .5 psig
10 bar/
145 psig
50 bar/
725 psig
100 bar/
1450 psig
200 bar/
2900 psig
Air 20 °C/68 °F 0.00 % 0.22 % 1.2 % 2.4 % 4.9 %
200 °C/392 °F -0.01 % 0.13 % 0.74 % 1.5 % 3.0 %
400 °C/752 °F -0.02 % 0.08 % 0.52 % 1.1 % 2.1 %
Hydrogen 20 °C/68 °F -0.01 % 0.10 % 0.61 % 1.2 % 2.5 %
200 °C/392 °F -0.02 % 0.05 % 0.37 % 0.76 % 1.6 %
400 °C/752 °F -0.02 % 0.03 % 0.25 % 0.53 % 1.1 %
Steam (satura-
ted steam) 100 °C/212 °F 0.26 % - - - -
180 °C/356 °F 0.17 % 2.1 % - - -
264 °C/507 °F 0.12 % 1.44 % 9.2 % - -
366 °C/691 °F 0.07 % 1.01 % 5.7 % 13.2 % 76.0 %
Characteristics and performance data
Frequency K-band (26 GHz technology)
Measuring cycle time 450 ms
Step response time 1) ≤ 3 s
Tracking speed of the measuring window
max. 1 m/min
Beam angle 2)
-
Horn antenna ø 75 mm (2.953 in) 10°
-
Horn antenna ø 95 mm (3.74 in) 8°
Emitted HF power 3)
1) Time span after a sudden measuring distance change by max. 0.5 m in
liquid applications, max 2 m with bulk solids applications, until the output
signal has taken for the first time 90 % of the final value (IEC 61298-2).
2) Outside the specified beam angle, the energy of the radar signal has a level
which is reduced by 50 % (-3 dB)
3) EIRP: Equivalent Isotropic Radiated Power
VEGAPULS 62 • Approval according to LPR radio standard 67
11 Supplement
41721
-EN
-120301