From 75b01dd48fc809daf55e285e1e807818dba55d44 Mon Sep 17 00:00:00 2001
From: Abraham Wolk <abraham.wolk@ess.eu>
Date: Thu, 22 Jan 2026 10:15:13 +0100
Subject: [PATCH] CSSTUDIO-3620 Bugfix: When no range is specified, the default
 range [0.0, 100.0] should only be set if there are no observed values to base
 the range on.

---
 .../widgets/linearmeter/LinearMeterRepresentation.java    | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/app/display/linearmeter/src/main/java/org/csstudio/display/extra/widgets/linearmeter/LinearMeterRepresentation.java b/app/display/linearmeter/src/main/java/org/csstudio/display/extra/widgets/linearmeter/LinearMeterRepresentation.java
index 4081cee78c..196ead3438 100644
--- a/app/display/linearmeter/src/main/java/org/csstudio/display/extra/widgets/linearmeter/LinearMeterRepresentation.java
+++ b/app/display/linearmeter/src/main/java/org/csstudio/display/extra/widgets/linearmeter/LinearMeterRepresentation.java
@@ -344,9 +344,11 @@ private void valueChanged(WidgetProperty<?> property, Object old_value, Object n
                                 meter.setRange(observedMin - 1, observedMax + 1, false);
                                 newObservedMinAndMaxValues = false;
                                 linearMeterScaleHasChanged = true;
-                            } else if (meter.linearMeterScale.getValueRange().getLow() != 0.0 || meter.linearMeterScale.getValueRange().getHigh() != 100) {
-                                meter.setRange(0.0, 100.0, false);
-                                linearMeterScaleHasChanged = true;
+                            } else if (Double.isNaN(observedMin) || Double.isNaN(observedMax)) {
+                                if (meter.linearMeterScale.getValueRange().getLow() != 0.0 || meter.linearMeterScale.getValueRange().getHigh() != 100) {
+                                    meter.setRange(0.0, 100.0, false);
+                                    linearMeterScaleHasChanged = true;
+                                }
                             }
                         }
                     }