Casella CEL Apex personal sampling pumps - Manual (Page 17)

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the buzzer will sound. When the problem lasts for three or more seconds, the pump motor will switch itself
OFF and remain OFF with the instrument still ON and displayed.
Normal operation cannot be resumed until the flow restriction has been removed. When the restriction is
removed, the pump may start again automatically; if it does not, switch the Apex unit OFF then ON again.
3.3
Bag Mode
This allows the pump to fill a gas bag and stop automatically when it is full.
1.
Use a suitable length of 5 mm (nominal internal diameter) tubing to connect the gas bag to the
pump outlet shown in Figure 2.
2. In Hold Mode, press or several times until FLOW SEt blinks on the display.
3. Press to select it.
4. Use to set the flow to less than 0.8 litres/min. The pump enters Bag Mode.
5. Press to start the pump.
The display will show BAG and a percentage flow, with no volume or time information.
6. Once the pump has started, and may be used to change the flow rate to a
different percentage.
When the back-pressure from the bag indicates that it is full, a FULL message will be displayed
and the pump stops automatically.
3.4 Use With Low Flow Adaptor
Outlet
Dry Cal Flowmeter
Dry Cal
®
Prim ary Flow Meter
v04019
Flow
Apex
Pump
Sorbent Tube
in Tube Holder
TEMP 19.48
2.5
Flow
Constant Pressure Regulator
Low Flow Adaptor
This enables the instrument to be used with sorbent tubes at flows down to 5 millilitres/min.
1.
Connect the inlet of an Apex unit to a flow meter such as the Defender or Dry flow meter
and calibrate the flow rate to 1.5 litres/min.
2. Stop the pump and disconnect the flowmeter.
3. Starting from the Apex inlet, connect the following: constant pressure regulator, low flow adaptor,
sorbent tube holder and a low flow flow meter such as the Dry Flow or Dry Cal shown in Figure 9.
4. Break both ends off a sorbent tube and put it in the holder with the arrow pointing towards the
pump.
5. Start the Apex pump and adjust the flow to the required rate using the screw on the side of the
low flow adaptor.
6. Perform the measurements using a fresh sorbent tube.
3.5 Fixed Duration Sampling (DUR)
This mode is available on both Apex and Apex Pro models to allow the pump to sample for a fixed period,
then switch off automatically when the period has elapsed. This feature is useful where a stated flow rate
Figure 9: Low flow adaptor arrangement