SKC 224-44XR Universal Pump - Manual (Page 15)

13
Setting or Verifying Flow Rate
When performing multiple-tube sampling using an adjustable
low fl ow holder (dual, tri, or quad), ensure the regulator has
been activated and the pump flow rate is set at 1.5 L/min.
The maximum fl ow rate through any one tube is 500 ml/min*.
Calculate the sum of all tube fl ow rates. If the sum is ≤ 1000 ml/
min, proceed with calibration and sampling without any further
adjustment to pump fl ow rate. If the sum is > 1000 ml/min, set
the pump fl ow rate 15% higher than the sum of tube fl ow rates.
* Back pressure across some sample tubes can be higher than average. In these instances,
the maximum fl ow rate of 500 ml/min per tube may not be achieved.
Before use, allow pump to equilibrate after moving it from one
temperature extreme to another.
Ensure pump has run for fi ve minutes before proceeding with calibration.
Ensure the pump is set for low fl ow (see Activating the Regulator,
page 10).
Connect the adjustable low fl ow holder (Figure 4, page 12) to the
pump intake (Figure 2, #6 on page 9) using 1/4-inch Tygon tubing.
Insert an opened sorbent tube into each rubber sleeve of the low
fl ow holder (Figure 4, #3 and 4) with the arrow on the tube pointing
toward the holder.
If sampling with fewer tubes than number of ports, insert
unopened sorbent tubes in the empty ports to seal them.
Note the fl ow rates specifi ed by each sampling method and add them
together. If the sum is ≤1000 ml/min, proceed to the next step. If the
sum is > 1000 ml/min, multiply the total tube fl ow rate by 1.15 and set
the pump for that fl ow rate.
Connect the exposed end of a sorbent tube to an external calibrator.
Remove the tamper-resistant cover from the face of the pump. Start the
pump using the on/off switch (Figure 2, #1). Turn the brass fl ow adjust
screw (Figure 4, #2) for the appropriate port of the low fl ow holder until
the desired fl ow rate is achieved. Turn clockwise to decrease the fl ow.
Connect holder to pump
intake and tube inlet to
calibrator.
2
continued on page 14
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