A Deflectograph is a survey vehicle used to produce data for the assessment of pavement strength. It is a lorry based system, with a pair of wheels at the front and a pair of double wheels at the rear. At the start of testing a pair of deflection beams are lowered onto the road surface. The Deflectograph then moves forward, so that the double wheels on the rear of the vehicle straddle the two beams. This causes the pavement to deflect (due to the vehicle’s weight) which is measured in the two beams. Once the rear wheels have reached the end of the beams, the beams are brought forward and the process is repeated again. This results in deflection measurements taken at approximately 4m intervals. These machines survey at 2.5km/h and are further discussed in HD29 (DMRB Volume 7 Section 3).
The Accreditation and QA requirements for these devices are given in the Accreditation and QA specification .
If you are looking for a contractor to carry out Deflectograph surveys compliant with HD29 on your behalf, you may wish to check the list of Deflectograph Survey devices below. On this page you can also find the latest accreditation certificates. In this table machines are referred to as having met criteria if they have met the mandatory criteria as defined in the Accreditation and QA specification for these devices. Some Network Authorities may also require a specific level of performance in some or all of the additional tests. Please see the certificates for more detail on the performance of these devices in these additional tests.
Certificates from previous years can be found here.
|ID||Reg plate||Operating Company||Met criteria||Certificate|
|02||L697 BKR||PTS||Yes||2017 DFG M02 (L697 BKR)|
|03||B180 FBL||TRL||Yes||2017 DFG M03 (B180 FBL)|
|05||D962 JRU||WDM Ltd||Yes||2017 DFG M05 (D962 JRU)|
|08||BYW 80V||WDM Ltd||Yes||2017 DFG M08 (BYW 80V)|
|09||VGV 182X||WDM Ltd||Yes||2017 DFG M09 (VGV 182X)|
|10||F569 JBB||WDM Ltd||Yes||2017 DFG M10 (F569 JBB)|
|12||EOU 230W||WDM Ltd||Yes||2017 DFG M12 (EOU 230W)|
|14||B195 CFW||Lincolnshire CC||Yes||2017 DFG M14 (B195 CFW)|
|15||ACZ 3268||DoE Northern Ireland||Yes||2017 DFG M15 (ACZ 3268)|
|16||B880 XOU||WDM Ltd||Yes||2017 DFG M16 (B880 XOU)|