bug fix with deleting the tool

hp4155/memristor_final/help.py

@@ -85,6 +85,8 @@ def test_contacts():
             print(f"R{i}{j}:{R} Ohm")
             #print(f"Contact check of smu{i} and smu{j} failed!")
     
+    del device
+    
 
 
 #double sweep from start to stop and then from start to stop

hp4155/memristor_final/memristor.py

@@ -274,6 +274,8 @@ def on_set_button_clicked(b):
         #unlock device
         device.inst.unlock()
 
+        del device
+        
         change_state(buttons)
         change_state(parameters)
         change_state(all_widgets)