... by the black granule on the filter paper (unit: Rb ). SV-2LB, equipped with Nixie tube, is easy to operate by ... and the average of them. Addition: The strong point of SV-2LB: Air compression is not needed while it works.The ... : 5mm, length: 5m. 9.Weight : 18kgs 10.Packing size :610x500x325mm SV-2LB Semi-automatic Filter Paper Smokemeter Smoke Meter/Opacimeter SHENGWEI ...