diff --git a/site_ansto/instrument/sans/config/hmm/detector.tcl b/site_ansto/instrument/sans/config/hmm/detector.tcl
index 9afa05fa..22f01a0f 100644
--- a/site_ansto/instrument/sans/config/hmm/detector.tcl
+++ b/site_ansto/instrument/sans/config/hmm/detector.tcl
@@ -7,10 +7,10 @@ if {$::sim_mode == "true"} {
 } else {
   makeasyncqueue acq ORHVPS ca1-quokka 4001
   evfactory new dhv1 orhvps acq
-  dhv1 lowerlimit 0
+  dhv1 lowerlimit 800
   dhv1 upperlimit 2400
   dhv1 tolerance 19
-  dhv1 max 2400
+  dhv1 max 2600
   dhv1 rate 10
 # dhv1 lock
 }