A tachograph needs recalibration at a fixed interval. How many years between recalibrations?

• A. Two years
• B. Eight years
• C. Four years
• D. Six years

Answer: (D)

Tachograph accuracy is kept in check by a fixed recalibration interval. The device must be recalibrated and re-verified at six-year intervals so its readings remain legally reliable for measuring driving time and speed. This six-year cycle reflects how long the calibration is considered valid under regulations and manufacturer guidance.

If major changes occur to the vehicle (like wheel/tire size changes or speed-sensor replacements) or if the unit shows faults, recalibration should happen sooner. But for normal operation, the standard period between recalibrations is six years.