 So the equipment that we're looking at here is what's known as a surface-effect segregation tester and with this equipment what we can do is to characterize the behavior of a free-flowing material when it is discharged into a into a bunker, silo, bin or small hopper. So in essence what this machine does is to homogenize a small sample of material which is held in the cube structure we have here. We'll see this operating in a moment. It homogenizes the material, the cube then stops rotating and the material is discharged down this inclined chute here. Built into the floor of the chute are a series of lips, these lips are the tops of these vertical shutters and this enables the capture of a thin bed of material on top of which subsequent material can then form what represents one side of a heap formation in a storage system filled with material. So the important characteristic that we need to capture here is how stable is the blend. In that context what we mean is if we load the material into a handling system do we find that the coarse particles separate away from the finer materials? Alternatively do we find that the higher density particles separate from the lower density particles or do we have separation by particle shape? This equipment enables us to examine whether or not these effects are present with our chosen bulk solid. So the principle of the tester then is to try and replicate a repeatable heap formation such as would be found in a bulk solid handling system and of course this is the function of the inclined plane that we see here. So the first step of the operation of this tester is to load material into the blending cube here. So material is loaded into the blending cube, the angle of the incline on this chute is configured to match the poured angle of repose of the material when we discharge it in there because what we want to obtain as close as possible is a fairly consistent bed depth from start to finish. So what we're going to see now is the homogenization stage then we're going to follow that with the discharge and then we're going to look at sample capture. So we've really pre-loaded material into the blending cube so now we turn this on and we can homogenize the material. For different materials this will require a different sort of duration and possibly a different sort of blending speed. So we've reached a condition now where the material has been homogenized within the blending cube and the blending cube has now been parked up over the top of this first segment section here. So what we now have to do is to discharge the material into the inclined plane. So gaining access like this we simply open the outlet and the material pours out so we then stop the flow of material and what we can see immediately in this situation is the fact that we've got a very coarse dominant deposition at the base of the slope of material. Although maybe not quite so obvious we have a coarse deficiency under the filling point. So this point here represents the apex of a deposited heap of free-flowing material in a storage system and this point down here represents the internal wall or a surface that's preventing the flow of material. So this basically is the centre line of the heap. This is the outside region. What we will now do is move on to extracting the samples. So having arrived at a segregated bed of material what we now need to do is to extract the samples. Now the samples we extract from this might be used for size analysis or they might be analysis of assay for the chemical content of them. But essentially the extraction is fairly straightforward and what this involves is isolating segments of our bed. So we start at the lower end of the slope and we're going to isolate the coarser content. We do this by raising the gate up like here so now we've created a segmented section of the bed here. We now come towards the apex of the heap. Now we don't want the material to the left of the apex because the slope length there is too short to catch any real mechanism. What we need is from the apex and into the next segment. So again what we do is to raise the gate up such as we see here and isolate that segment. So now what we need to do is to take the samples out of here. So it's simply a case of dropping the floor out of the equipment like so to give us a sample from the base and doing the same at the top of the slope to give us material from the apex. So having extracted the samples from the test rig what I've now done is to decant these into clear jam jars to help visualise the differences here. And what we can see here is a clear jar containing the sample from the base of the heap of the tester of the storage structure whereas the material underneath the apex is usually typified by being less free flowing and less mobile and therefore we find concentration of that underneath the fill point. So we've extracted the samples from the test apparatus and normally these could be used for either size analysis or chemical analysis or sometimes returned to the client for flavour testing. But the principles apply to a very wide range of products whether we're talking about high performance cements whether we're talking about food products, fertilisers, other blended materials. If it's a free flowing material there's always a high risk of these sort of variations in composition occurring once we begin to handle the material and the more handling steps the material goes through the greater the risk can become and of course the severity of this on the process is going to be dictated not only by the material characteristics which we obtain from this machine but also by the operating performance of the handling equipment through which that material passes i.e. is it mass flow or is it a core flow system? The core flow of course giving us the worst case scenario whereby the segregation that invariably develops during loading is then amplified by preferential extraction of material from the base of that storage system.