diff --git a/devices/field_z.properties b/devices/field_z.properties
index 0929c3f..3730e60 100644
--- a/devices/field_z.properties
+++ b/devices/field_z.properties
@@ -1,6 +1,6 @@
-#Fri Dec 11 16:10:26 CET 2015
-maxValue=0.0
-minValue=0.0
+#Fri Dec 11 16:10:56 CET 2015
+maxValue=20.0
+minValue=-20.0
 offset=0.0
 precision=0
 resolution=NaN