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��U24b3diUl VL ONEX NEW;RK VAPOR SAMPU%I MI-VAUS - _Vacuum/Volurr�System Operation Ie oInstzuctions forAT 1000AndAT 1001 VacuumNolumeSystem Follow these steps after probe rods have been driven to sampling depth and expendable or retractable point has been disengaged or after PRT tubing has been attached 1. Turn the vacuum pump on and allow vacuum to build in the vacuum tank Make sure a that the line valve is closed before starting the pump. The inside scale of the vacuum gauge is calibrated in inches b zs standard temperature and pressure).a Pump the tank down to the desired vacuated for volume in um anditers .J0 turn the switch off. 2. Attach the vacuum hose to the top of the soil vapor sampling train(i.e to sampling cap on top of probe rods or to PRT tubing). 3. Open the Ione control valve. for each rod used. SIf sampling through probe rods,evacuate 100 ml ofvolume vacuum gauge calibrated to ome protocols may tail for a minimum of 3 purge volumes to be inches Hg and volume in liters. evacuated before sampling(i.e.9 foot depth=3 rods x 100 ml x 3=900 ml). If using PRT tubing,evacuate the appropriate volume to purge the ambient air in the system. You mY choose to purge a standard volume at each sample location. 4. After achieving sufcientPurge volume, quickly close the cine valve and allow sample line pressure to return to Zero(0). This returns the sampling train to atmospheric pressure. 7be sample can be collected at this time. Pointers If the needle on the line gauge does not return to atmospheric pressure after the line Z. ;- valve is shut(which disconnects the vacuum source),it may indicate that the soil at the sampling depth is saturated or that the pore space is too tight to yield a sample. It could also indicate that the sampling train is plugged. depth is very permeable or that there is a leak in the sampling If the needle moves back to zero very quickly,it indicates that the soil at the ram linoControl panel with line control valve and tine train. You can ch r pck fPressure gauge. Ieaks by laying out the sampling train and plugging the sampling end with a rubber stopper and applying a vacuum to it. You may want to do this before sampling. In some soils the needle may return to zero very slowly once the valve line is shut. The time it takes for the needle to return to zero is called the`recovery"time. It should be noted for each sample taken This information will allow relative comparison of soil o permeability. Recovery times greater than 10 minutes should be considered suspect The effect of any leakage in the sampling r After 10 minutes,the operator should consider ewer increased with lodger recovery times. o location,length of pullback from the sampling tip,or switching g ng entirrsampling from sol gas P a � sampling to grab sampling and analysis of soil. cl 12 VDC Vacuum Pump and Tank. 3.9 n�