diff --git a/src/main/java/edu/iris/dmc/station/RuleEngineRegistry.java b/src/main/java/edu/iris/dmc/station/RuleEngineRegistry.java
index 769f32c..c8bc9ce 100644
--- a/src/main/java/edu/iris/dmc/station/RuleEngineRegistry.java
+++ b/src/main/java/edu/iris/dmc/station/RuleEngineRegistry.java
@@ -171,7 +171,7 @@ private void defaultChannelRules(Set<Integer> set) {
 		}
 		if (!set.contains(321)) {
 			add(321, new InstrumentCodeUnitsCondition(true,
-					"If Channel:Code[2] == (H | L | M | N) then Stage[1]:InputUnit must equal *m/s* AND Stage[Last]:OutputUnits must equal count*"),
+					"If Channel:Code[2] == (H | L | N) then Stage[1]:InputUnit must equal *m/s* AND Stage[Last]:OutputUnits must equal count*"),
 					Channel.class);
 		}
 		if (!set.contains(332)) {
diff --git a/src/main/java/edu/iris/dmc/station/conditions/InstrumentCodeUnitsCondition.java b/src/main/java/edu/iris/dmc/station/conditions/InstrumentCodeUnitsCondition.java
index 6308bc0..0b75d44 100644
--- a/src/main/java/edu/iris/dmc/station/conditions/InstrumentCodeUnitsCondition.java
+++ b/src/main/java/edu/iris/dmc/station/conditions/InstrumentCodeUnitsCondition.java
@@ -70,7 +70,7 @@ public Message evaluate(Channel channel) {
 
 		
 
-		if("HLMN".indexOf(code.charAt(1)) >=0 | "hlmn".indexOf(code.charAt(1)) >=0) {
+		if("HLN".indexOf(code.charAt(1)) >=0 | "hln".indexOf(code.charAt(1)) >=0) {
 			if(!inputUnit.toLowerCase().contains("m/s")) {
 				nestedMessage.add(Result.warning("Instrument code " +code.charAt(1)+" should have stage 1 input units similar to *m/s* but input units are "+inputUnit));
 				returnmessage=true;