Honeywell SLG 700 User Manual page 117

is inaccurate, it might be necessary to adjust the reflection models as described above.
However, in order to tune the surface and interface models properly, a minimum upper
product thickness of approximately 20cm is required.
Tuning of linear attenuation
The linear attenuation for vapor will generally be correct for most applications and may not need
any tuning. However, the linear attenuation for the upper product will vary significantly from
application to application and the default value might not be appropriate. The upper product linear
attenuation describes how fast the radar pulse intensity decays with distance as it travels through
the upper medium. A precise upper product linear attenuation is therefore important in 2-liquid
flooded and 2-liquid non-flooded applications. A procedure to tune the upper product linear
attenuation is as follows:
1. Collect a minimum of two processed full echos. One for a thin interface (20 cm) and
one for a thick interface (the thicker the better). Ensure that the interface level is
away from any disturbances that may affect the reflection amplitude.
2. In the Correlation Algorithm page, select the thin interface echo and place the
surface and interface models at the surface and interface reflection, respectively (if
not already done automatically).
3. Adjust the Interface model gain so the model matches the interface reflection
4. Select the thick interface echo and place the models appropriately
5. Adjust the upper product linear attenuation so that the interface model matches the
interface reflection
6. If the tuned interface gain and upper product linear attenuation provide a good model
match for interface for both echos, click apply
Revision 5
SLG 700 Series HART Option User's Manual
Page 109