diff --git a/pytec/pytec/gui/view/param_tree.json b/pytec/pytec/gui/view/param_tree.json
index fc6134b..3a85d83 100644
--- a/pytec/pytec/gui/view/param_tree.json
+++ b/pytec/pytec/gui/view/param_tree.json
@@ -148,7 +148,7 @@
                      "step": 0.1,
                      "limits": [
                         0,
-                        5
+                        4
                      ],
                      "siPrefix": true,
                      "suffix": "V",
@@ -199,6 +199,7 @@
                "type": "float",
                "value": 10000,
                "step": 1,
+               "min": 0,
                "siPrefix": true,
                "pinSiPrefix": "k",
                "suffix": "Ω",
@@ -381,7 +382,7 @@
                      "decimals": 6,
                      "step": 0.1,
                      "limits": [
-                        -2,
+                        0,
                         2
                      ],
                      "siPrefix": true,