Filters are made of quartz and the up-side is rugged and uneven, while on the down-side there is a weak square pattern. They are wrapped in aluminium foil and stored in plastic zip bags.
Before sampling, filters shall be stored in a clean place and changing filters shall also be done indoors in a clean room. Try not to touch the filter or the inside of the aluminium foil, which is in contact with the filter with the hands.
1.
Switch the pump on (see below).
Measure the flow rate (see below). 2.
3.
4.
Switch the pump off.
Put the PM10 inlet head aside. Remove the filterholder (Figure 1) from the sampler and take it indoors.
5.
6.
Unfold the aluminium foil which the filter was stored in before sampling.
Open the filter holder (by removing the upper frame) and take the filter at
7.
the edges (outside the sampled area) with the pairs of tweezers and put it on the aluminium foil. Fold the filter once, so that the sampled area faces inwards, Fold the aluminium foil and put it back in the plastic bag.
Open the aluminium foil with a new filter. The up-side should be facing upwards. Place it on the supporting net of the filter holder and check that it is covering the whole area of the net, so that the upper frame seals properly
8.
9.
10.
11.
against the filter. Do not overtighten the screws of frame, because the filter is fragile and may crack.
Install the filter holder in the sampler and put the PM10 inlet in place.
Switch the pump on
Measure the flow rate. If it is higher than it should be, the filter may not be sealed and there is an air leakage
Switch the pump off.
The sampler has a temperature sensor placed in the funnel below the filter (Fig 2a and 2b).
It gives a voltage signal, which changes according to the flow rate. The signal can be measured at the socket on the inside of the door of the house (Fig 3 and 4). It is placed to the right of the grey box containing a timer (not used). Inside the grey box there is a 6.3
A/250 V fuse (Fig 5a and b). If the fuse is broken, there will be no signal. There is a cable inside the house to connect to a 230 V power supply. On the inside of the door a calibration factor is written 10.4 V= 1.2 m3/min. (It was measured using another pump).
Signal with the pump switched off: 6.83 V
Signal with no filter: 11.47 V (2.3 m3/min). (this pump)
Signal with a new filter: 11.05 V (1.7 m3/min) (this pump)
1.
2.
Plug in the cable.
Place the filter holder with a new filter in the sampler.
3.
4.
Switch the pump on and measure the signal (Fig 4)
After sampling is finished, switch the pump on and measure the signal again.
The pump is a blower with a rated power of 1.5 kW and voltage 220-240 V. The pump is controlled by a remote mobile phone system, with 4 relays. The pump is connected to relay number 3. The phone has a Sonera Easy SIM card valid for 1 year.
The number is 040 3257558 and the PIN code 8140 (the envelope for the card with number and PIN code is in a box in the container beside the phone)
To switch the pump on : Dial the number and then dial 031 (0=to get in contact, 3=relay no 3 and 1=pump on)
To switch the pump off : Dial 030 (the last 0=pump off)

To check the status of the pump : Dial 111 and for each relay you will hear a tone: a short blip when the relay is off and a long buzzing tone when the relay is on. So when the pump is on you shall hear. Blip, blip, buzz, blip. The buttons have to be pressed firmly but not too long and wait between each number till you here a respons blip. An easier way of doing this control is to go to the container and check if the pump is on.
Figure 1
Figure 2a Figure 2b

Figure 3 Figure 4
Figure 5a Figure 5b

Store sampled filters in refridgerator before sending them in a soft envelope by mail to:
Ulla Wideqvist
Stockholm University
Dept. of Applied Environmental Science (ITM)
Air Laboratory
106 91 Stockholm
Sweden
Phone: +46 8 6747161
E-mail: ulla.wideqvist@itm.su.se