Texas Instruments Calculator-Based Ranger CBR

The CBR uses a sonic sensor to measure the time between transmitting a short ultrasonic pulse and receiving the first returned echo. The built-in microprocessor calculates the distance of the object in the range between 0.5 m (1.5 ft) and 6 m (20 ft) by doing a speed-of-sound calculation with a maximum of 200 samples per second. Then it computes the first and second derivatives of the distance data with respect to time to obtain velocity and acceleration data. These data are stored in lists and transferred under program control to one of the graphing calculators.