M25B SITE, STAINES: SITE INFORMATION
The M25B site is approximately 100 metres northbound of the M25A site, 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 February 2004 and is equipment with a range of ambient gas analysers, a TEOM configured to measure PM10 and PM2.5, a unit to measure sulphur dioxide and hydrogen sulphide. Due to changes in the layout of the carriageway associated with major roadworks during 2004 and 2004, there were noticeable periods of data loss and variations in source strengths. The sample inlet was placed in its final position in November 2005.
| Site | M25, Staines |
|
Location |
Clockwise carriageway, between junction 13 and 14 |
|
Grid reference |
TQ 025725 |
|
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
|
1.9 m |
|
Gaseous inlet distance from hard shoulder
|
1 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 M25B Staines here
| 2004 | Summary Statistics | |||
| 2005 | ||||
| 2006 | ||||
| 2007 | ||||
| 2008 |