diff --git a/300s School/NUCE 2113 - Radiation Detection and Measurement/Laboratory 4.md b/300s School/NUCE 2113 - Radiation Detection and Measurement/Laboratory 4.md
index 4c6748f2..c16cf74c 100644
--- a/300s School/NUCE 2113 - Radiation Detection and Measurement/Laboratory 4.md	
+++ b/300s School/NUCE 2113 - Radiation Detection and Measurement/Laboratory 4.md	
@@ -18,3 +18,5 @@ February 11th, 18:04
 14. 238
 15. 169
 
+Background count 56 2 minutes - 0.48 
+