A valve tester system is disclosed that comprises a valve tester assembly for rotating a valve stem of a valve. The valve tester assembly may include a support, a rotation element mounted on the support for rotating a valve during a rotation event, a control element for controlling aspects of the rotation event of the valve by the rotation element, and an element for detecting a location of the valve tester assembly during the rotation event of the valve. In some embodiments of the invention, the element for detecting the location of the valve tester assembly includes a Global Positioning Satellite (GPS) receiver. In some embodiments, the GPS receiver is integral with the control element.