diff --git a/src/cal_tools/tools.py b/src/cal_tools/tools.py
index 2d15866ac2517bc0925e2b6ad5bad10560f5ab36..88c533282c4abe94a9b8ee60640b37807e40b23f 100644
--- a/src/cal_tools/tools.py
+++ b/src/cal_tools/tools.py
@@ -880,6 +880,41 @@ def save_constant_metadata(
         const_mdata["creation-time"] = None
 
 
+def load_constants_dict(
+    retrieved_constants: dict,
+    empty_constants: Optional[dict] = None,
+    ) -> Tuple[dict, dict]:
+    """Load constant data from metadata in the
+    retrieved_constants dictionary.
+
+    :param retrieved_constants: A dict. with the constant filepaths and
+      dataset-name to read the constant data arrays.
+      {
+        'Constant Name': {
+            'file-path': '/gpfs/.../*.h5',
+            'dataset-name': '/module_name/...',
+            'creation-time': str(datetime),},
+        }
+    :param empty_constants: A dict of constant names keys and
+      the empty constant array to use in case of not non-retrieved constants.
+    :return constant_data: A dict of constant names keys and their data.
+    """
+    const_data = dict()
+    when = dict()
+
+    for cname, mdata in retrieved_constants.items():
+        const_data[cname] = dict()
+        when[cname] = mdata["creation-time"]
+        if when[cname]:
+            with h5py.File(mdata["path"], "r") as cf:
+                const_data[cname] = np.copy(
+                    cf[f"{mdata['dataset']}/data"])
+        else:
+            const_data[cname] = (
+                empty_constants[cname] if empty_constants else None)
+    return const_data, when
+
+
 def load_specified_constants(
     retrieved_constants: dict,
     empty_constants: Optional[dict] = None,