2.3 Setting up the sampler
Power
This GENT sampler operates with 220-230V, 50 Hz. The power consumption is about 0.3 kW.
The unit is expected to be setup in a specialised housing that protects the unit from direct contact to the ambient environment, i.e. hot and cold air temperature, high humidity, direct sunlight etc.. Usually the sampler is installed in a special housing, for example in an air quality sampling station. In special cases it might be appropriate to install the sampler in a laboratory space and to use a less than 100 m long pipe to connect the SFU to the pump. In same areas, for example in Mongolia in winter where the air temperature may drop below -30 ºC, this might be the only feasible way to run the GENT sampler.
Timer
The timer is provided with the GENT sampler and is located inside the transparent sampler box. It is located in the inside of a grey metal box. Instructions how to set up the timer are located in the inside of the grey cover. It is recommended to follow the instructions.
Turn off mains power before opening the grey box this is best done by disconnecting the sampler plug from the mains supply.
Open the grey box. Adjust the current time by pulling slightly on the yellow disk, that also holds the turn on and turn off markers. Then, while pulled out, turn the yellow disk until the time corresponds to the local time. Do not attempt to move the timer needle. Now, you can set the start and stop time by unscrewing the markers and by moving them along the outer cycle. Tightly fix the markers at the desired time marks.
Note that this timer does not automatically correct for summer and winter time. You may need to adjust the clock settings manually. Page: 14
The best way is to operate on standard time at all times throughout the year saves having to make any confusing adjustments.
If sampling does not commence at the desired time of the day, check for mains power and for operation of the timer clock. If the clock does not turn, then the timer is broken. For emergencies, you may run the GENT sampler manually by bypassing the timer by setting the ‘silver’ handle, which is sitting below the yellow disk to manual. For automatic operation, turn the lever back to automatic timer position.
Don’t turn off the mains power after sampling has been completed, otherwise the timer will stop operating.
The sampler is expected to be connected to mains power continuously; otherwise the timer will not operate. If the sampler is run manually, than the mains power may be disconnected after sampling.
Flow rate
For this programme, the flow rate used for airborne particulate matter sampling was agreed to be 16 – 17 lpm. This flow rate can be adjusted in a test run.
1. Completely install the GENT sampler.
2. Connect piping from SFU to sampler.
3. Load coarse and fine filters in stacked cassette.
4. Install cassette properly into black container.
5. Turn on GENT sampler.
6. Close valve.
7. Check for vacuum leaks.
8. Adjust flow rate on flow rate meter by turning valve from closed to open until the recommended flow rate has been achieved.
Now the GENT sampler should be ready for operation. Note: Don’t forget to replace the coarse and fine filters before commencing the sampling. You may keep the test filters