Regular calibration of your Bowmonk or Tapley brake testing / decelerometer equipment is essential in order to ensure that the equipment continues to provide accurate readings and to maintain legal compliance. Bowmonk is able to offer a range of calibration services.


Calibration Intervals

Our recommended calibration intervals for UK customers are shown below. Different intervals may apply to export markets.

BrakeCheck (all variants) – calibration required every year
Bowmonk VI & 2000 – calibration required every year
AFM2 Runway Friction Tester – calibration required every year
TintTesta – calibration required every year or every 2,500 tests
Tyre Depth Gauges – calibration required every year
Tyre Pressure Gauges – calibration required every year
Brakemeter / Dynometer – calibration required every year
Please note that in the UK it is mandated to have portable brake testing equipment calibrated at least every year if used for MOT testing purposes. If you are a non-UK customer then please check with your local authority for the applicable regulations regarding calibration intervals.

Calibration Notification

The next calibration due date is shown on a sticker affixed to the side of all our devices except the AFM2. All our electronic instruments (including the AFM2) automatically include the next calibration date on every receipt produced.

In addition the devices notify users that calibration is due as follows:

  • BrakeCheck (all variants) – a warning LED flashes 14 days before calibration is due, remaining permanently lit thereafter.
  • Bowmonk VI & 2000 – an on-screen message appears on/after the due date.
  • AFM2 Runway Friction Tester – the due date is shown briefly on-screen every time the instrument starts, and an on-screen “service” message appears on/after the due date.
  • TintTesta – a warning LED flashes 14 days before calibration is due, remaining permanently lit thereafter. The LED is also permanently lit if the maximum number of tests has been exceeded.
  • Brakemeter / Dynometer – no notification (refer to sticker).

Calibration Procedure

UK customers
We aim to make the calibration procedure for decelerometers as easy as possible. If we have your contact details then a month or so before your unit is due for calibration we will write to you to remind you that calibration is shortly due.

When the calibration is due you simply need to return the device using your own choice of courier. Only the testing device itself is required for calibration, so external accessories (e.g. chargers, brackets, cases, etc.) do not need to be returned.

Once your unit is received by us we operate a same day turnaround wherever possible. Your unit will then be returned to you by 24/48 hour carrier, unless you have arranged with us to upgrade the return shipping method.

Please enclose your reminder and/or your company contact details with your brakemeter.

Non UK Customers

When your decelerometer is due for calibration please  contact us first. Extra customs and/or courier charges may apply if you do not follow our instructions.

Return Address for all Calibrations:

FAO: Calibration Dept
Bowmonk Ltd
Diamond Road
Tel: +44 (0) 1603 485 153

The importance of Genuine Calibration

For any type of testing or measuring equipment it is vital that calibration services are carried out by laboratories which:


  • adhere to the requirements stipulated by the product’s approval authority (e.g. DVSA);
  • carry out calibrations in accordance with the manufacturer’s approved instructions.

As the manufacturer of the above devices, Bowmonk is perfectly placed to provide fast, efficient and cost-effective calibration services.

The brake meter will be calibrated to a procedure using a purpose built dedicated inclinable test rig.
Meters of Bowmonk manufacture: The reading is taken from the side of the recording needle, which touches the main needle on meters of Bowmonk manufacture.
Meters of Tapley manufacture: The reading is taken from the reading displayed on the scale between the two arrows on meters of Tapley manufacture. Bowmonk BrakeCheck/Tapley EBM: The reading is taken from the digital display of the BrakeCheck/Tapley EBM shown as a percentage. During the calibration process we will adjust your BrakeCheck/Tapley EBM to ensure it is reading as close to optimum performance as possible in order to ensure best ongoing functionality unless otherwise requested.

Should your Brakemeter require any additional service or adjustment work, we will advise you in advance.

The brakemeter will be calibrated within the limits specified by the DVSA which states that performance readings shall be accurate to within +/-3 % of the true value in g. Uncertainty of measurement: +/- 1.0 % g. Taking these figures into account, Bowmonk Ltd operates a +/- 2.0 % g pass tolerance.
These results relate only to the item calibrated.

The calibration will include a calibration certificate unless otherwise requested by the customer. The date for the next calibration will be shown on a label on the brakemeter unless otherwise requested by the customer