diff --git a/qiskit_experiments/library/characterization/t1.py b/qiskit_experiments/library/characterization/t1.py
index 643b213ca6..3ff24d35c6 100644
--- a/qiskit_experiments/library/characterization/t1.py
+++ b/qiskit_experiments/library/characterization/t1.py
@@ -127,6 +127,8 @@ def circuits(self) -> List[QuantumCircuit]:
         Raises:
             ValueError: When conversion factor is not set.
         """
+        if self.backend:
+            self._set_backend(self.backend)
         prefactor = self.experiment_options.conversion_factor
 
         if prefactor is None:
diff --git a/qiskit_experiments/library/characterization/t2ramsey.py b/qiskit_experiments/library/characterization/t2ramsey.py
index 84b0bce963..c86846259b 100644
--- a/qiskit_experiments/library/characterization/t2ramsey.py
+++ b/qiskit_experiments/library/characterization/t2ramsey.py
@@ -142,6 +142,8 @@ def circuits(self) -> List[QuantumCircuit]:
         Raises:
             ValueError: When conversion factor is not set.
         """
+        if self.backend:
+            self._set_backend(self.backend)
         prefactor = self.experiment_options.conversion_factor
 
         if prefactor is None: