**3. Results**

We present results from two viewpoints. One aspect is the reduction of different pollutants over the scrubber at tests on HFO. This is interesting from the viewpoint of which substances in the exhaust gas that can be expected to be removed in the scrubbing process, and to what extent. We also compare emissions downstream of the scrubber with emissions from LSFO combustion. This is an interesting comparison to make from an environmental point of view since both solutions are alternatives to comply with existing regulation on sulphur in marine fuel and corresponding emissions. In addition, the composition of particles is presented and discussed separately.

The summary of results for specific fuel oil consumption and emissions are presented in Table 2, and further elaborated upon in the following text.

Uncertainties in the results cannot be described by the coefficient of variation alone. In addition, uncertainty is added from difficulties in determining the fuel flow. We estimate a load-dependent uncertainty of the specific fuel oil consumption (SFOC) which of approximately ±10% at 50% engine load and lower, and ±5% at more than 50% engine load for this engine and measurement. Determination of the dilution ratios is another source for uncertainties as well as the handling of samples in the rough environment in the funnel. Uncertainties in the PM sampling system setup further includes a loss of particles in the system that increases with the length of the transfer line from the exhaust gas channel to the dilutor.
