diff --git a/crpptbx/TCV/gdat_tcv.m b/crpptbx/TCV/gdat_tcv.m
index dd01515f7655a92a48e993e5e1534a69b332ea77..a413e5ec5a848a0e895d29a16745e7f7d58324fb 100644
--- a/crpptbx/TCV/gdat_tcv.m
+++ b/crpptbx/TCV/gdat_tcv.m
@@ -1762,6 +1762,13 @@ if strcmp(data_request_eff(1:2),'ne')
   gdat_data.error_bar_raw = gdat_data.error_bar;
   gdat_data.error_bar = gdat_data.error_bar_raw * diag(tracefirrat_data);
   gdat_data.data_fullpath=[gdat_data.data_fullpath '; fir_thom_rat ; _raw without firrat'];
+  ij=find(~isnan(tracefirrat_data));
+  if isempty(ij)
+    gdat_data.data_fullpath=[gdat_data.data_fullpath ' WARNING use ne_raw since firrat has NaNs thus ne=NaNs; fir_thom_rat ; _raw without firrat'];
+    disp('***********************************************************************')
+    disp('WARNING: ne from Thomson has fir_thom_rat with Nans so only ne_raw can be used');
+    disp('***********************************************************************')
+  end
 end
 z=mdsdata('\diagz::thomson_set_up:vertical_pos');
 gdat_data.dim=[{z};{time}];