Hi Radhoo,
I did these two tests:
All cpm are a mean on an hour.

I run 1 hour of measurements with the SI8B and SBM20 and I found a conversion factor of 0.0011081.
SBM20 = 16.27 cpm = 0.1028 usv/h (conv. 0.006315)
SI8B = 92.77 cpm = conversion factor 0.0011081 (I assume the same value measured with SBM20 0.1028 usv/h)

I run a parallel measurement with a bgeigie nano kit and I found a difference on the mean values on one hour of 0.00546 usv/h.
SI8B = 92.75cpm (conv 0.0011081)= 0.1027825 usv/h
Bgeigie= 32.5cpm (conv 0.002994) = 0.097324 usv/h

So I think that a conversion factor of 0.0011081 can be a good value, what do you think?

OrtoSystem