Arja Whiteside (X) Sep 23, 2011:

Tachographs are devices that are fitted by law to all goods and passenger vehicles above a certain capacity (3.5t in the EU). These devices record onto circular paper-based charts the speed of the vehicle, different types of driver activity and the distance travelled (and sometimes additional information, such as engine speed and fuel consumption) over a 24-hour period.


Tachograph heads are of either analogue or digital types
The recording medium for analogue heads are wax coated paper discs, and for digital heads are digital driver cards containing a microchip with flash memory. Digital driver cards store data as a .ddd file that can be imported into tachograph analysis software.

Arja Whiteside (X) Sep 23, 2011:

The analogue chart must be EU type approved. The country of type approval can be found on the rear of the chart, i.e. a mark of E4 would indicate the chart to have been approved in the UK for use in the EU.
Digital tachographs make tampering much more difficult by sending signals in an encrypted manner. EU regulation 1360/2002 makes digital tachographs mandatory for all vehicles described in the above section Regulations and manufactured after August 1, 2005.

Digital tachographs would be required as of May 1, 2006 for all new vehicles for which EWG regulation VO(EWG)3820/85 applies, as is published in the official newsletter of the European Union L102 from April 11, 2006.