Hach-Lange BUEHLER 3010 4010 4210 4410 Manual - Manual (Page 27)

Operation
Page 27 Manual BÜHLER BU4010ff
Function of the VAR Flow-proportional sampling system
· Before the system can be used, it must be calibrated. In the automatic calibration cycles (5
cycles), the respective volumes must entered.
· At the flow-proportional (variable) sampling system the sample volume is directly entered in ml by
means of the keys at the control when editing a sampling program.
· After the program start the pinch valve is closed.
· A pressure (air produced by the diaphragm pump) is applied to the metering vessel via the air
connection. Thus the hose is purged.
· Now, the valve system switches to vacuum and the depression generated by the diaphragm pump
withdraws the air from the metering vessel. A vacuum is generated and leads to the drawing-off of
sample medium at the connected hose.
· The medium is sucked into the Dosingvessel over the Measuring tube (2).
· during inlet, the sample volume already will be measured in the measuring tube(2) and only the
requested volume remains in the vessel.
· After measuring is done, the system is ventilated by opening the air inlet (4) so that the water in
the suction hose can flow back to the extraction point.
· After a pre-programmed aeration time, the pinch valve (6) opens in two steps and the sample is
filled into a container.
Cleaning:
To clean the metering vessel (5), open the screw cap (glass) or turns to the left (plastic, bayonet
shutter), pull the silicone discharge hose to the front and remove the metering vessel.
The measuring tube (2) can be cleaned with a bottle brush BM60560 .