Soak wood chips in water 30 minutes; drain.
Combine dill, juice, mustard, and salt, stirring well. Place salmon, skin side down, in a shallow baking dish; brush mustard mixture over salmon. Cover and refrigerate 20 minutes.
Prepare the grill for indirect grilling, heating one side to low and leaving one side with no heat. Maintain temperature at 200° to 225°.
Place wood chips on hot coals. Place a disposable aluminum foil pan on unheated side of grill. Pour 2 cups water in pan. Coat grill rack with cooking spray; place on grill. Place salmon, skin side down, on grill rack over foil pan on unheated side. Close lid; cook 35 minutes or until fish flakes easily when tested with a fork or until desired degree of doneness.