diff --git a/src/main.py b/src/main.py
index 33611b3..77c7876 100644
--- a/src/main.py
+++ b/src/main.py
@@ -98,6 +98,30 @@ def chain_layer_to_target(layer_object):
     material_object = call_material_from_elabid(target_elabid)
     return material_object
 
+def deduplicate_instruments_from_layers(layers):
+    lasers = []
+    chambers = []
+    rheeds = []
+    for lyr in layers:
+        instruments = lyr.get_instruments(apikey)
+        lasers.append(instruments["laser_system"])
+        chambers.append(instruments["deposition_chamber"])
+        rheeds.append(instruments["rheed_system"])
+    instruments_used_dict = {
+        "laser_system": list( set( lasers ) ),
+        "deposition_chamber": list( set( chambers ) ),
+        "rheed_system" : list( set( rheeds ) ),
+    }
+    # lasers = { f"layer_{lyr.layer_number}": lyr.laser_system for lyr in layers }
+    # chambers = { f"layer_{lyr.layer_number}": lyr.deposition_chamber for lyr in layers }
+    # rheeds = { f"layer_{lyr.layer_number}": lyr.rheed_system for lyr in layers }
+    # instruments_used_dict = {
+    #     "laser_system": lasers,
+    #     "deposition_chamber": chambers,
+    #     "rheed_system": rheeds,
+    # }
+    return instruments_used_dict
+
 def make_nexus_schema_dictionary(substrate_object, layers):
     pld_fabrication = {
         "sample": {
@@ -115,6 +139,7 @@ def make_nexus_schema_dictionary(substrate_object, layers):
             },
             "multilayer": {},
         },
+        "instruments_used": deduplicate_instruments_from_layers(layers),
     }
     multilayer = pld_fabrication["sample"]["multilayer"]
     for layer in layers: