diff --git a/script/DelayScan.py b/script/DelayScan.py
index c1f79e8..5c9a67d 100644
--- a/script/DelayScan.py
+++ b/script/DelayScan.py
@@ -278,7 +278,7 @@ def _startPlot(type):
             caput(OTF_ESET,en)
             wait_channel(OTF_DONE, 1, type = 'i')
             Scan(Delay_Time)
-            if polperscan=2:
+            if polperscan==2:
                 switchpol(2,RUNTYPE)
                 Scan(Delay_Time)
                 switchpol(1,RUNTYPE)