Parameters of tune explanations

Hello all,

I would like to understand the differents parameters of tune like Cell entrance, Energy discriminator,... but mainly OmegaBias and Deflect ? 

When I launch an autotune in the batch, the intensities of middle mass (89) is below than our criteria (<1000 count) but when I modify the Omega Bias and Deflect, the intensities is above 1000 count, why the instrument doesn't it choose the configuration for the best intensity ?

I use the ICP-MS 7900 Agilent.

Thanks you in advance for your returns ,

Philippe