M25 SITE, STAINES: SITE INFORMATION
The second of the rural locations is situated at the edge of the
clockwise carriageway of the London orbital motorway, between junctions 13
and 14, to the west of London, in Surrey. It is just to the north of
Staines and is approximately 3 km south west of Heathrow airport. The
monitoring facility is of a similar design to the second M4 motorway site.
Traffic flows at this site are considerably higher than those at the other
locations, with typical daily flows of 175,000 and peak hour flows of
between 12,000 and 15,000 vehicles.
The site became operational during the middle of 1995. It was equipped with a series of ambient gas analysers, which were supplemented towards the end of 1995 with a TEOM configured to measure PM10, and towards the end of 1999 by a second TEOM configured to measure PM2.5. During the middle of 1997 a unit to measure sulphur dioxide and hydrogen sulphide was installed.
| Site | M25, Staines |
|
Location |
Clockwise carriageway, between junction 13 and 14 |
|
Grid reference |
TQ 02730 73480 |
|
Road type |
Rural motorway |
|
Commencement date |
5/95 |
|
PM10 inlet height above ground
level |
2.7 m |
|
PM10 inlet height above enclosure
roof |
0.7 m |
|
PM2.5 inlet height above ground
level |
2.4 m |
|
PM2.5 inlet height above enclosure
roof |
0.4 m |
|
Particulate inlet distance from hard shoulder
|
4.05 m |
|
Gaseous inlet height above ground level
|
1.5 m |
|
Gaseous inlet distance from hard shoulder
|
0.5 m |
|
Gaseous manifold inlet gas flow rate
|
6.1m/sec |
|
Gaseous residence time |
0.8 sec |
|
Wind vane and anemometer distance from hard
shoulder |
5.05 m |
|
Wind vane and anemometer height above ground
level |
3.75 m |
|
Wind vane and anemometer height above enclosure
roof |
1.75 m |
|
Temperature & relative humidity sensor
height above ground level |
2.1 m |
|
Temperature & relative humidity sensor
distance from hard shoulder |
5.05 m |
|
Pyranometer sensor height above ground level
|
3.45 m |
|
Pyranometer sensor height above enclosure
roof |
1.45 m |
|
Pyranometer sensor distance from hard
shoulder |
4.5 m |
|
Carbon monoxide (CO) |
Infra red (IR) absorption |
|
Total oxides of nitrogen (NOX),
nitrogen dioxide (NO2), nitric oxide (NO)
|
Chemiluminescence |
|
Ozone (O3) |
Ultra violet (UV) absorption |
|
Total hydrocarbons (THC), methane
(CH4), non-methane hydrocarbons (NMHC) |
Flame ionisation detector (FID) |
|
Sulphur dioxide (SO2), hydrogen
sulphide (H2S) |
Ultra violet (UV) fluorescence |
|
Particulate matter (PM10 and
PM2.5) |
Heated gravimetric |
Download the archive for M25 Staines here
| 1995 | 2000 | Summary Statistics | ||
| 1996 | 2001 | 2005 | ||
| 1997 | 2002 | 2006 | ||
| 1998 | 2003 | 2007 | ||
| 1999 | 2004 |
See photographs of M25 Staines here