Due to the Red War, the Black Armory lost access to its forge in the EDZ. Since then, Ada-1 has been unable to locate it herself. Though she maintains a distrust for Guardians, Ada-1 hands you a weapon frame in case you are able to locate the forge. With this frame, you will be able to craft a black armory weapon, but not before calibrating it and bringing it back to Ada-1.
Follow the steps to calibrate the weapon frame.