A system is provided for calibrating a production module having a production module transmitter and a production module receiver. A calibrated reference module includes a calibrated reference module transmitter and a calibrated reference module receiver. A first pulse generator is coupled to the calibrated reference module. A second pulse generator is coupled to the production module. A first attenuator is coupled between the calibrated reference module receiver and the production module transmitter. A second attenuator is coupled between the production module receiver and the calibrated reference module transmitter. The calibrated reference module and the production module are optic modules.
