[Dav3dum]

Dear users!
The problem i'm currently working on is that i'd like to calculate the volume Flow over a specified surface.
The code i'm using is this:

type            surfaceRegion;
libs            ("libfieldFunctionObjects.so");

writeControl    timeStep;
writeInterval   1;
writeFields     false;
log             false;
region air
regionType    sampledSurface;
name        sampleSurfaceDict;

sampledSurfaceDict
        {           	
			type sampledTriSurfaceMesh;
			surface samplingsurface1.stl;
			regionType cells;		
                        interpolate true;
		}
        



fields (U);
operation areaNormalIntegrate;

however I get this error massage:Unknown function type sampledTriSurfaceMesh

if you could help me to solve this problem i'd really appreciate that.
Yours sincerly,
David