Radar Speed Sensors

To tune or adjust the ROS device for the speed sensor connected to the system:

  1. Make sure any section switches are turned OFF before powering the ROS device on.

  2. Select the Settings icon on the bottom right of the screen. The Settings Menu will open.

  3. Locate and select the Speed Settings module.

  4. Select the Recal Distance button to reset the distance display to a “0” value.

  5. Drive 1 mile [1 kilometer]. The field computer will measure the distance driven using the current speed cal value.

    Note:  Accelerate and decelerate slowly. To achieve the most accurate calibration, do not use the vehicle odometer or ROS distance display to measure the actual distance driven. Use section lines or highway markers to determine the actual distance.

  6. At the end of the driven distance, view the distance display again and record the value. The ROS distance should read a value of approximately 5280 [1000]. If the display reads between 5260-5300 [990-1010], the default value of 598 [152] is accurate for the speed cal value.

  7. If the distance displayed is not between 5260-5300 [990-1010], recalculate the speed cal with the formula:


    where ADJ = Adjusted Speed Cal, CSC = Current Speed Cal (speed cal number used to drive the test distance), and D = the ROS Distance display at the end of the driven distance. Round to the nearest whole number.

    Note:  For Example, assume that the ROS Distance reads 5000 [980] after a known 1 mile distance has been driven using an initial speed cal value of 598 [152].

    English Metric

    The Adjusted Speed Cal value is 631 [155]

  8. Select the speed cal value for the radar speed sensor and use the on-screen keypad to enter the adjusted speed cal.

  9. Verify the new speed cal derived from the equation by repeating steps 4 through 6.

Last Revised: Jul 2024