Siemens SITRANS LG260 Operating Instructions Manual page 64

Influence of the superimposed gas and pressure on measurement 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 vapours.
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
Air
Hydrogen
Steam (saturated
steam)
Characteristics and performance data
Measuring cycle time
Step response time
4)
Max. filling/emptying speed
Ambient conditions
Ambient, storage and transport temperature
Ʋ Standard
Ʋ CSA, Ordinary Location
Process conditions
For the process conditions, please also note the specifications on the type label. The lowest value
always applies.
The measurement error through the process conditions in the specified pressure and temperature
range is < 1 %.
Process pressure
Vessel pressure relating to the flange
nominal pressure stage
Time span after a sudden measuring distance change by max. 0.5 m in liquid applications, max 2 m with bulk
4)
solids applications, until the output signal has taken for the first time 90 % of the final value (IEC 61298-2).
64
Temperature
1 bar (14.5 psig)
20 °C (68 °F) 0 %
200 °C (392 °F) -0.01 %
400 °C (752 °F) -0.02 %
20 °C (68 °F) -0.01 %
200 °C (392 °F) -0.02 %
400 °C (752 °F) -0.02 %
100 °C (212 °F) 0.26 %
180 °C (356 °F) 0.17 %
264 °C (507 °F) 0.12 %
366 °C (691 °F) 0.07 %
SITRANS LG260 - Operating Instructions
10 bar (145 psig)
0.22 %
0.13 %
0.08 %
0.1 %
0.05 %
0.03 %
-
2.1 %
1.44 %
1.01 %
< 500 ms
≤ 3 s
1 m/min
Products with high dielectric constant (>10) up to 5 m/
min.
-40 ... +80 °C (-40 ... +176 °F)
-40 ... +60 °C (-40 ... +140 °F)
-1 ... +40 bar/-100 ... +4000 kPa (-14.5 ... +580 psig),
depending on the process fitting
see supplementary instructions manual "Flanges ac-
cording to DIN-EN-ASME-JIS"
Pressure
50 bar (725 psig)
1.2 %
0.74 %
0.52 %
0.61 %
0.37 %
0.25 %
-
-
9.2 %
5.7 %
PBD-51041061