UltraGauge Tyre Size Calibration
How to calibrate distance using the GPS method
This distance calibration method is based on using GPS speed. GPS speed is most accurate when driving in a straight line at a constant speed.
Step 1: Adding a speed gauge to the screen (ie: On page 1 of the UltraGauge)
- Press the menu button and then access Gauge/Page Menu – Select Gauge/Page – Select Gauges – Page 1 Gauges
- Use the up and down keys to navigate to the KPH gauge
- Press Menu, this will cause the cursor to blink
- Press up and down until the number 1 is next to the KPH gauge
- Press Menu again to lock the gauge into page 1, position 1
- Leave the menu by pressing back etc
- The UltraGauge should now be displaying the KPH gauge on page 1, position 1 (top left hand corner of the screen)
Step 2: Take you calculator and GPS speed device (ie: iPhone) to your car and head to a stretch of road, preferably a long straight stretch of road
Step 3: While driving at a constant speed for around 30 seconds, note the speed reading output on both the GPS speed device (ie: iPhone) and the readout on the UltraGauge. The readings could be different.
Step 4: Find a safe place to pull over and park. With your calculator complete the following, GPS speed divided by UltraGauge speed
Step 5: Adjust the ‘Distance Cal’ factor in your UltraGauge
- Navigate to Menu – Vehicle Setup – Calibration – Calibrate Distance
- Note the distance value shown by the UltraGauge and on the calculator multiply this by the factor found in step 4
- Press Menu and then press up or down to adjust the distance value to the calculated value
- Press Menu to store the updated distance value. The UltraGauge now shows the Disatance cal value
- Leave the Menu by selecting back etc
Step 6: To check the values are correct please drive along and check once again the GPS speed device value versus that of the UltraGauge output speed
Step 7: Make fine adjustments as required by re-completing the above steps to correct UltraGauge speed output value