A testing system calibration instrument includes a plurality of device inputs, a plurality of signal processing units, a display device, a controller and a housing that unifies the components. The plurality of signal processing units includes two or more of a millivolt/volt signal reader configured to produce a first calibration signal based on a millivolt/volt signal received from a first calibration sensor through one of the device inputs, a decoder configured to produce a second calibration signal based on an encoded signal received from a second calibration sensor through one of the device inputs, and a voltmeter configured to produce a third calibration signal based on an analog voltage signal received from a third calibration sensor through one of the device inputs. The controller is configured to control the display device to display information relating to the first calibration signal, the second calibration signal and/or the third calibration signal.