diff --git a/notebooks/Gotthard2/Characterize_Darks_Gotthard2_NBC.ipynb b/notebooks/Gotthard2/Characterize_Darks_Gotthard2_NBC.ipynb
index bf2384afb09c59108e739a9ab9493d8adaf8f7b8..3ecf9f72b38e5f15c8a8e3895f62160140f9b0f4 100644
--- a/notebooks/Gotthard2/Characterize_Darks_Gotthard2_NBC.ipynb
+++ b/notebooks/Gotthard2/Characterize_Darks_Gotthard2_NBC.ipynb
@@ -99,6 +99,17 @@
     "%matplotlib inline"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "bc4a9824",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Input parameters validation\n",
+    "gotthard2lib.validate_sensor_type(sensor_type)"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,
diff --git a/notebooks/Gotthard2/Correction_Gotthard2_NBC.ipynb b/notebooks/Gotthard2/Correction_Gotthard2_NBC.ipynb
index 478719287185de554a953965039c62d6550ee8b6..b44d20e869d32179b79deb47c9d6e666ec330c7a 100644
--- a/notebooks/Gotthard2/Correction_Gotthard2_NBC.ipynb
+++ b/notebooks/Gotthard2/Correction_Gotthard2_NBC.ipynb
@@ -106,7 +106,6 @@
     "import warnings\n",
     "from logging import warning\n",
     "\n",
-    "import h5py\n",
     "import pasha as psh\n",
     "import numpy as np\n",
     "import matplotlib.pyplot as plt\n",
@@ -132,6 +131,17 @@
     "%matplotlib inline"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "fc893eff",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Input parameters validation\n",
+    "gotthard2lib.validate_sensor_type(sensor_type)"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,
diff --git a/notebooks/Gotthard2/Summary_Darks_Gotthard2_NBC.ipynb b/notebooks/Gotthard2/Summary_Darks_Gotthard2_NBC.ipynb
index 9b03e08e39185fc2a98f62e2fd3efc55dfab0328..adda2211f2a982e967940dc40818b5eb480cd6cd 100644
--- a/notebooks/Gotthard2/Summary_Darks_Gotthard2_NBC.ipynb
+++ b/notebooks/Gotthard2/Summary_Darks_Gotthard2_NBC.ipynb
@@ -69,6 +69,16 @@
     "from cal_tools.tools import CalibrationMetadata"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Input parameters validation\n",
+    "gotthard2lib.validate_sensor_type(sensor_type)"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,
diff --git a/src/cal_tools/gotthard2/gotthard2lib.py b/src/cal_tools/gotthard2/gotthard2lib.py
index e13e5ad1e142c123a9dc387f2c91a0141d14574b..faacc8add6096bc8b733b3c3d6aac80fcf98f60e 100644
--- a/src/cal_tools/gotthard2/gotthard2lib.py
+++ b/src/cal_tools/gotthard2/gotthard2lib.py
@@ -3,6 +3,16 @@ from pathlib import Path
 from typing import List, Union
 
 import extra_data
+import numpy as np
+
+
+def validate_sensor_type(sensor_type):
+    choices = ["25um", "50um"]
+    if sensor_type and sensor_type not in choices:
+        raise ValueError(
+            f"Unexpected Gotthard2 `sensor_type` given: '{sensor_type}'. "
+            f"Valid options are: {', '.join(choices)}."
+        )
 
 
 def map_da_to_source(dc, das, source_template, karabo_id, affixes):
@@ -70,8 +80,6 @@ class Gotthard2Ctrl():
         Returns:
             str: return if its a 25um or 50um detector.
         """
-        import numpy as np
-
         hostnames = self.run_dc.get_run_value(self.ctrl_src, "rxHostname")
         num_hosts = np.count_nonzero(hostnames != b'')
         if num_hosts == 0: