Quote: (Originally Posted by
iani)

The plastic plate in the OPV has now been replaced by a larger version, supposedly this reduces the likelihood of lime getting stuck, I have certainly found lime in my OPV in the past and it is a good source of problems trying to pull a negative. The OPV seems to work better when wet so I now dampen it before doing a neg test.
Ian
yesterday 350m+ in Russel with new modified OPV had full loop flood and had to come out on OC.
Grain in OPV
btw RMV 35LPM