Specifications

Table Of Contents
248
Reference Manual
00809-0100-4026, Rev HA
Appendix C: Advanced configuration
November 2014
Advanced Configuration
C.4.3 Double bounce
A double bounce echo is an echo that has been reflected against the tank roof then down to the
surface before being detected by the transmitter.
Double bounces are commonly present in spherical or horizontal cylinder tanks. In this case, the
tank roof can sometimes amplify the double bounce echo amplitude. Normally, double bounce
echoes appear when the tank is 60-70 % full. In these cases, the double bounce echo can cause
the transmitter to lock onto the wrong echo.
The Double Bounce function is used for managing problems with echoes appearing in the tank
because of the tank shape stronger than the surface echo itself.
The Double Bounce Offset is given by the following formula:
Double Bounce Offset = B - 2*A,
where A is the distance from the Tank Reference Point to the product surface, and B is the
distance from the Tank Reference Point to the Double Bounce echo. In many cases, the Double
Bounce Offset is given by the height of the nozzle.
Note that the surface echo is required to suppress the double bounce. If the surface echo enters
the hold off distance region, there is no product surface reference and the double bounce might
be interpreted as the surface echo.
A
B
Double bounce offset=B - 2*A
Amplitude
Distance