diff --git a/300s School/NUCE 2113 - Radiation Detection and Measurement/Laboratory 1.md b/300s School/NUCE 2113 - Radiation Detection and Measurement/Laboratory 1.md
index fd9f2ee0d..65108302b 100644
--- a/300s School/NUCE 2113 - Radiation Detection and Measurement/Laboratory 1.md	
+++ b/300s School/NUCE 2113 - Radiation Detection and Measurement/Laboratory 1.md	
@@ -21,3 +21,12 @@ Exercise 1.3
 | 200/1000    | 1.24V   |
 
 - [ ] Do exercise 1.4 where we make a linear relationsihp of above data
+
+| Attenuation Switches | Voltage |
+| -------------------- | ------- |
+| All 1x               | 4.00 V  |
+| 2x                   | 2.10 V  |
+| 5x                   | 0.94 V  |
+| 10x                  | 0.398 V |
+| 2x 5s                | 0.400 V |
+Third column is needed to compare measured voltage to 1x voltage