Gas & vapour sampling using sorbent tubes, 30cm diameter breathing zone – SKC Limited Sidekick Pump Step By Step Guide User Manual

Page 13

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224-G3 Issue C

Page 11

Gas & Vapour Sampling using Sorbent Tubes

the CPC should be on the side connected to the
low flow adaptor and tube holder.

3. Take one of the sorbent tubes and break off both

ends, ideally using a purpose designed tube tip
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

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

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