Abstract: A position determination system comprises a data processing system, a first measuring module, and a second measuring module. Both of the measuring modules are coupled to the data processing system. The first measuring module includes a first sensing device for obtaining positional data of a first testing target. A calibration sensing device is rigidly linked to the first sensing device. The positional relationship between the first sensing device and the calibration target is known. The system has a rotation mechanism for rotating the sensing device of the first sensing device. The second measuring module includes a second sensing device for obtaining positional data of a second testing target. A calibration target is rigidly linked to the second sensing device, and is used with the calibration sensing device to obtain a positional relationship between the calibration target and the calibration sensing device. The positional relationship between the second sensing device and the calibration target is known.

Abstract: A cordless vehicle wheel alignment sensor head with interchangeable batteries includes easy to replace rechargeable batteries, thus eliminating the need for a service call to replace the batteries and allows the operator to swap a nearly depleted battery set with a fully or partially charged battery set. The sensor head includes a battery compartment door which slides upwards without pivoting about or detaching from the sensor head, and allows the batteries to pop out and be replaced. The battery compartment door also includes at least one battery engaging protrusion which presses against the battery at a non-contacting end of the rechargeable battery when the battery compartment door is closed. Accordingly, with the battery compartment door closed, the battery is tightly held in place and pressed into a pair of retractable pins that result in electrically coupling the battery to the sensor circuitry.