The tripmeter is switched on by means of the switch on the base of the meter. The switch is moved from the 0 pressed position to the 1 pressed position. The meter digits will light up when the power is ON. Controls: The remote reset button will zero the lower distance display. The metallic switch on the face of the meter has three positions, and will normally be in the central position. If this switch is moved upwards to the FREEZE position it will stop the top TOTAL display from incrementing. This facility is useful if the competitor wishes to preset the TOTAL distance figure to a certain value which will be reached at a known certain point on the road, or the TOTAL reading is too high and the vehicle needs to travel a distance without the TOTAL distance being increased. The downward position of this switch zero's both readouts on the Clubman version of the Brantz International 2 meter and just the top TOTAL readout on the 'Pro' Brantz model. This switch should be operated momentarily when the tripmeter is first switched on. The STEP control above the three-position switch is to edit the TOTAL readout value. It is a rotary control which is normally fully anti-clockwise until a 'click' is felt. Turning this control clockwise will cause the TOTAL readout to step itself which enables the competitor to set the TOTAL readout to any figure. This facility is useful to align the TOTAL readout value to a value given, say, by the organizer's handbook at a certain point. The control marked + and - is fitted to the 'Pro' models and allows the tripmeter to count upwards or downwards (+ is incrementing, or upwards). Calibration: The meter is calibrated to be accurate on any vehicle fitted with any type of Brantz sensor and using any wheel size or gearing by means of the three thumbwheel switches on the lower right hand corner marked CALIBRATION. If the meter is to show hundredths of a kilometre then the thumbwheel switches are first set to 100. Find the start of an accurately measured kilometre and momentarily press all the reset (zero) controls. Drive the measured kilometre and stop accurately at the end of the distance. Note the figure which has come up on both readouts. This is the calibration figure for this particular setup of the vehicle. Enter this figure onto the calibration thumbwheel switches. The accuracy of the meter can be confirmed by turning the vehicle around and traveling back over the measured kilometre. The measured kilometre should be read by the Brantz very accurately as 1.00 kilometre. To calibrate in hundredths of a mile, follow the above calibration procedure exactly, but substitute the word 'mile' for the word 'kilometre'. If several wheel / tyre sizes and gearings are available for the vehicle then repeat the calibration procedure for each combination & note down the different calibration figures. Long distance events: Certain of the Brantz 'Pro' models which contain the letter 'D' in their serial number can shift the decimal place of the top TOTAL readout one place to the right so that the TOTAL will indicate 999.9 kilometres or miles which is a useful facility for certain international events. The tripmeter cannot change from one mode to the other after being switched on. On power-up, the tripmeter normally will be in standard mode (99.99) kilometres or miles, but if the T.ZERO switch is held in the downwards (zeroing) position WHILST THE METER IS BEING SWITCHED ON then the normal mode will be reselected.