SKC Limited Universal Pump Step By Step Guide - Manual (Page 13)

www.skcltd.com 224-G3 Issue C Page 11
Gas & Vapour Sampling using Sorbent Tubes
breaker (such as SKC part no. 800-01200). Take
care handling the tube as the broken ends
are extremely sharp. Fit the sorbent tube into
the short black hose of the low flow adaptor.
To determine the correct way the sorbent tube
should face, look for a printed arrow on the tube. If
present the arrow should point towards the pump.
The arrow represents the correct direction of the
airflow through the tube. If there is no arrow on the
tube, the largest air gap or unfilled section of the
tube should face away from the pump, that is, to
atmosphere.
4. With the sorbent tube in place in the low flow
adaptor a connection from the free end of the
sorbent tube is made to the hosetail on the Defender
flow calibrator marked 'Suction', as shown.
Tube adaptor for small
diameter sorbent tubes
Tube must be held
vertical during
calibration
For small diameter sorbent tubes use the tube
adaptor to make the connection to the free end
of the sorbent tube. Switch on the pump and flow
calibrator, and set the calibrator to take continuous
readings.
Ensure that the sorbent tube is held
vertically during calibration. Adjust the air flow
rate through the sorbent tube by turning the throttle
valve screw in the side of the low flow adaptor
using the large bladed screwdriver attachment of
the toolkit, as shown above. Once the flow rate is
set to the required level (depending on tube type
and sampling method), switch off the pump.
5. The sorbent tube used to set the flow rate is now
removed from the tube holder and replaced with a
clean tube with both ends broken off. The exposed
end of the tube should be protected with the tube
cover, which screws onto the low flow adaptor.
One of the red plastic caps provided can be used
to seal the sorbent tube until the sample is taken,
however please note that the cap should not be
pressed on too far as they are designed to provide
an airtight seal for transportation. Once pushed fully
home the caps require cutting off with a sharp knife.
Tube Cap
Tube Cover
6. Mount the sample train (comprising the sample
pump, tubing, tube holder and tube cover) onto
the worker who is to wear it during the sample.
The tube holder should be mounted vertically on
the worker, and as close to the breathing zone
as is practical and comfortable. The pump can
be either clipped to a belt or placed into a pouch.
Note that the connecting tube can present a
hazard if left to flap around, in much the same way
as a necktie. Measures should be taken to protect
the wearer by clipping or restraining the tube so
that it cannot become caught up in anything.
30cm
Diameter
Breathing
Zone
Once the pump is mounted on the worker in a
satisfactory way it can be switched on. IMPORTANT:
The start time of the sample should be noted.