diff --git a/src/ProcessBus.App.Wpf/Controls/WaveformPanelControl.cs b/src/ProcessBus.App.Wpf/Controls/WaveformPanelControl.cs
index d3870ec8..a9f1800b 100644
--- a/src/ProcessBus.App.Wpf/Controls/WaveformPanelControl.cs
+++ b/src/ProcessBus.App.Wpf/Controls/WaveformPanelControl.cs
@@ -41,6 +41,8 @@ public sealed class WaveformPanelControl : FrameworkElement
     private double _currentAutoPeak;
     private DateTime _voltagePeakUpdatedUtc = DateTime.MinValue;
     private DateTime _currentPeakUpdatedUtc = DateTime.MinValue;
+    private string? _voltageUnit;
+    private string? _currentUnit;
     private const double AutoScaleHeadroom = 1.28;
     private const double AutoScaleSmoothing = 0.18;
     // Steady-state deadband: the observed window peak jitters a little every cycle, and an
@@ -64,6 +66,15 @@ public WaveformPanelControl()
             typeof(WaveformPanelControl),
             new FrameworkPropertyMetadata(null, FrameworkPropertyMetadataOptions.AffectsRender));
 
+    // A reused WPF control must never carry a raw-count peak range into a
+    // different SV publisher. Stream identity is cheap state, not packet work.
+    public static readonly DependencyProperty StreamKeyProperty =
+        DependencyProperty.Register(
+            nameof(StreamKey), typeof(string), typeof(WaveformPanelControl),
+            new FrameworkPropertyMetadata(string.Empty,
+                FrameworkPropertyMetadataOptions.AffectsRender,
+                static (d, _) => ((WaveformPanelControl)d).ResetScaleState()));
+
     public static readonly DependencyProperty ShowModeProperty =
         DependencyProperty.Register(
             nameof(ShowMode),
@@ -112,6 +123,42 @@ public WaveformSnapshot? Snapshot
         set => SetValue(SnapshotProperty, value);
     }
 
+    public string StreamKey
+    {
+        get => (string)GetValue(StreamKeyProperty);
+        set => SetValue(StreamKeyProperty, value);
+    }
+
+    private void ResetScaleState()
+    {
+        _voltageAutoPeak = 0;
+        _currentAutoPeak = 0;
+        _voltagePeakUpdatedUtc = DateTime.MinValue;
+        _currentPeakUpdatedUtc = DateTime.MinValue;
+        _voltageUnit = null;
+        _currentUnit = null;
+    }
+
+    private void ResetLaneScaleWhenUnitsChange(bool isVoltage, string unit)
+    {
+        if (isVoltage)
+        {
+            if (!WaveformAutoRangePolicy.UnitsChanged(_voltageUnit, unit))
+                return;
+            _voltageUnit = unit;
+            _voltageAutoPeak = 0;
+            _voltagePeakUpdatedUtc = DateTime.MinValue;
+        }
+        else
+        {
+            if (!WaveformAutoRangePolicy.UnitsChanged(_currentUnit, unit))
+                return;
+            _currentUnit = unit;
+            _currentAutoPeak = 0;
+            _currentPeakUpdatedUtc = DateTime.MinValue;
+        }
+    }
+
     public string ShowMode
     {
         get => (string)GetValue(ShowModeProperty);
@@ -355,6 +402,7 @@ private double ResolveLaneAmplitudeMax(LaneDefinition lane, IReadOnlyList<Wavefo
         // A raw-count voltage lane is still the voltage lane. Its history
         // must not share the current lane auto-range, nor adopt fixed A/V scales.
         var isVoltage = string.Equals(lane.Title, "Voltage", StringComparison.OrdinalIgnoreCase);
+        ResetLaneScaleWhenUnitsChange(isVoltage, lane.Unit);
         var hasPhysicalUnits = string.Equals(lane.Unit, isVoltage ? "V" : "A", StringComparison.OrdinalIgnoreCase);
         var scaleText = isVoltage ? VoltageScale : CurrentScale;
 
@@ -447,7 +495,10 @@ private double ResolvePeakHoldScale(bool isVoltage, double targetPeak)
 
         if (isVoltage)
         {
-            if (targetPeak >= _voltageAutoPeak || (now - _voltagePeakUpdatedUtc).TotalSeconds > PeakHoldSeconds)
+            // A 1000× counts-to-V conversion (or sudden real magnitude change)
+            // must not be hidden as a flat line for the entire hold timeout.
+            if (WaveformAutoRangePolicy.ShouldReleasePeakHold(_voltageAutoPeak, targetPeak) ||
+                (now - _voltagePeakUpdatedUtc).TotalSeconds > PeakHoldSeconds)
             {
                 _voltageAutoPeak = targetPeak;
                 _voltagePeakUpdatedUtc = now;
@@ -459,7 +510,8 @@ private double ResolvePeakHoldScale(bool isVoltage, double targetPeak)
             return Math.Max(_voltageAutoPeak, 1.0);
         }
 
-        if (targetPeak >= _currentAutoPeak || (now - _currentPeakUpdatedUtc).TotalSeconds > PeakHoldSeconds)
+        if (WaveformAutoRangePolicy.ShouldReleasePeakHold(_currentAutoPeak, targetPeak) ||
+            (now - _currentPeakUpdatedUtc).TotalSeconds > PeakHoldSeconds)
         {
             _currentAutoPeak = targetPeak;
             _currentPeakUpdatedUtc = now;
diff --git a/src/ProcessBus.App.Wpf/MainWindow.xaml b/src/ProcessBus.App.Wpf/MainWindow.xaml
index e5ff7c6a..95e4d51d 100644
--- a/src/ProcessBus.App.Wpf/MainWindow.xaml
+++ b/src/ProcessBus.App.Wpf/MainWindow.xaml
@@ -922,6 +922,7 @@
                             <ListView Grid.Row="2"
                                       Style="{StaticResource GridListViewStyle}"
                                       ItemsSource="{Binding Streams}"
+                                      Margin="0,10,0,0"
                                       SelectedItem="{Binding SelectedStream, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
                                       ClipToBounds="True"
                                       ScrollViewer.HorizontalScrollBarVisibility="Disabled"
@@ -1927,48 +1928,11 @@
                                     <ColumnDefinition Width="320"/>
                                 </Grid.ColumnDefinitions>
                                 <Grid.RowDefinitions>
-                                    <RowDefinition Height="Auto"/>
-                                    <RowDefinition Height="Auto"/>
+                                    <RowDefinition Height="0"/>
+                                    <RowDefinition Height="0"/>
                                     <RowDefinition Height="*"/>
                                 </Grid.RowDefinitions>
 
-                                <Border Grid.Column="0"
-            Grid.Row="0"
-            Style="{StaticResource DenseGroupBorderStyle}"
-            Padding="8">
-                                    <WrapPanel>
-                                        <Border>
-                                            <Border.Style>
-                                                <Style TargetType="Border" BasedOn="{StaticResource MetricChipBorderStyle}">
-                                                    <Setter Property="Visibility" Value="Visible"/>
-                                                    <Style.Triggers>
-                                                        <DataTrigger Binding="{Binding WaveformHeaderFrequencyText}" Value="N/A">
-                                                            <Setter Property="Visibility" Value="Collapsed"/>
-                                                        </DataTrigger>
-                                                    </Style.Triggers>
-                                                </Style>
-                                            </Border.Style>
-                                            <TextBlock Foreground="{StaticResource AccentBrush}"
-                           FontWeight="SemiBold"
-                           Text="{Binding WaveformHeaderFrequencyText}"/>
-                                        </Border>
-                                        <Border Style="{StaticResource MetricChipBorderStyle}">
-                                            <TextBlock Foreground="{StaticResource AccentBrush}"
-                           FontWeight="SemiBold"
-                           Text="{Binding WaveformHeaderWindowText}"/>
-                                        </Border>
-                                        <!-- Advanced waveform-shape inference is diagnostic, not a
-                                             primary oscilloscope KPI. Keep it on hover, not as a
-                                             constantly competing warning-colored pill. -->
-                                        <Border Style="{StaticResource MetricChipBorderStyle}"
-                                                Visibility="Collapsed"
-                                                ToolTip="{Binding WaveformShapeStatusText}">
-                                            <TextBlock Foreground="#B1CBE0"
-                                                       Text="{Binding WaveformShapeStatusText}"/>
-                                        </Border>
-                                    </WrapPanel>
-                                </Border>
-
                                 <Border x:Name="ScopeHeroPanel"
             Grid.Column="0"
             Grid.Row="2"
@@ -2116,6 +2080,7 @@
                                         <controls:WaveformPanelControl Grid.Row="2"
                                                                    d:Visibility="Collapsed"
                                            Snapshot="{Binding Waveform}"
+                                           StreamKey="{Binding SelectedStream.StreamId}"
                                            ShowMode="{Binding WaveformShowMode}"
                                            LayoutMode="{Binding WaveformLayoutMode}"
                                            TimebaseMode="{Binding WaveformTimebase}"
@@ -2194,9 +2159,7 @@
                                                 <DockPanel LastChildFill="False">
                                                     <TextBlock DockPanel.Dock="Left" Text="Measurements"
                                                                Style="{StaticResource PanelTitleTextStyle}"/>
-                                                    <TextBlock DockPanel.Dock="Right" VerticalAlignment="Center"
-                                                               Text="{Binding WaveformHeaderFrequencyText}"
-                                                               FontSize="11" Foreground="#8CBDE4"/>
+                                                    
                                                 </DockPanel>
                                                 <DockPanel Margin="0,7,0,2">
                                                     <Button DockPanel.Dock="Right" Content="Copy" Margin="7,0,0,0"
@@ -2389,35 +2352,62 @@
                                                                    ToolTip="{Binding AnalogValues.Ic.AngleDisplayText}"/>
                                                     </Grid>
                                                 </Border>
-                                                <Expander Margin="0,8,0,0" Header="Power &amp; calibration"
-                                                          IsExpanded="False"
-                                                          Foreground="#B9D7EE">
-                                                    <StackPanel Margin="3,7,3,0">
-                                                        <TextBlock Text="{Binding EngineeringScaleExplanation}"
-                                                                   Foreground="#F4C66D" FontSize="11"
-                                                                   TextWrapping="Wrap" Margin="0,0,0,6"/>
-                                                        <UniformGrid Columns="2">
-                                                            <StackPanel Margin="0,0,4,6">
-                                                                <TextBlock Text="P" Foreground="#89AFCB" FontSize="10"/>
-                                                                <TextBlock Text="{Binding TotalActivePowerText}" Foreground="#F4FAFF" TextTrimming="CharacterEllipsis"/>
+                                                <!-- Estimated from nominal engineering scaling; confidence remains explicit. -->
+                                                <Border Margin="0,8,0,0" Padding="4,7"
+                                                        BorderThickness="0,1,0,0" BorderBrush="#24415B">
+                                                    <StackPanel>
+                                                        <DockPanel Margin="0,0,0,5" LastChildFill="False">
+                                                            <TextBlock DockPanel.Dock="Left" Text="Power estimate"
+                                                                       Foreground="#A6CBE3" FontSize="11"
+                                                                       FontWeight="SemiBold"/>
+                                                            <TextBlock DockPanel.Dock="Right" Text="UNVERIFIED"
+                                                                       Foreground="#D4B36C" FontSize="9.5"
+                                                                       ToolTip="{Binding EngineeringScaleExplanation}"/>
+                                                        </DockPanel>
+                                                        <UniformGrid Columns="4">
+                                                            <StackPanel Margin="0,0,3,0">
+                                                                <TextBlock Text="P" Foreground="#8DAFCA" FontSize="9.5"/>
+                                                                <TextBlock Text="{Binding TotalActivePowerText}" Foreground="#EEF8FF"
+                                                                           FontSize="10.5" FontFamily="Consolas"
+                                                                           TextTrimming="CharacterEllipsis"
+                                                                           ToolTip="{Binding TotalActivePowerText}"/>
                                                             </StackPanel>
-                                                            <StackPanel Margin="0,0,0,6">
-                                                                <TextBlock Text="Q" Foreground="#89AFCB" FontSize="10"/>
-                                                                <TextBlock Text="{Binding TotalReactivePowerText}" Foreground="#F4FAFF" TextTrimming="CharacterEllipsis"/>
+                                                            <StackPanel Margin="0,0,3,0">
+                                                                <TextBlock Text="Q" Foreground="#8DAFCA" FontSize="9.5"/>
+                                                                <TextBlock Text="{Binding TotalReactivePowerText}" Foreground="#EEF8FF"
+                                                                           FontSize="10.5" FontFamily="Consolas"
+                                                                           TextTrimming="CharacterEllipsis"
+                                                                           ToolTip="{Binding TotalReactivePowerText}"/>
                                                             </StackPanel>
-                                                            <StackPanel Margin="0,0,4,0">
-                                                                <TextBlock Text="S" Foreground="#89AFCB" FontSize="10"/>
-                                                                <TextBlock Text="{Binding TotalApparentPowerText}" Foreground="#F4FAFF" TextTrimming="CharacterEllipsis"/>
+                                                            <StackPanel Margin="0,0,3,0">
+                                                                <TextBlock Text="S" Foreground="#8DAFCA" FontSize="9.5"/>
+                                                                <TextBlock Text="{Binding TotalApparentPowerText}" Foreground="#EEF8FF"
+                                                                           FontSize="10.5" FontFamily="Consolas"
+                                                                           TextTrimming="CharacterEllipsis"
+                                                                           ToolTip="{Binding TotalApparentPowerText}"/>
                                                             </StackPanel>
-                                                            <StackPanel>
-                                                                <TextBlock Text="PF" Foreground="#89AFCB" FontSize="10"/>
-                                                                <TextBlock Text="{Binding PowerFactorText}" Foreground="#F4FAFF" TextTrimming="CharacterEllipsis"/>
+                                                            <StackPanel Margin="0,0,3,0">
+                                                                <TextBlock Text="PF" Foreground="#8DAFCA" FontSize="9.5"/>
+                                                                <TextBlock Text="{Binding PowerFactorText}" Foreground="#EEF8FF"
+                                                                           FontSize="10.5" FontFamily="Consolas"
+                                                                           TextTrimming="CharacterEllipsis"
+                                                                           ToolTip="{Binding PowerFactorText}"/>
                                                             </StackPanel>
                                                         </UniformGrid>
-                                                        <TextBlock Text="{Binding EvidenceCopyStatusText}" Foreground="#89AFCB"
-                                                                   FontSize="10" TextTrimming="CharacterEllipsis"/>
+                                                        <Expander Margin="0,7,0,0" Header="Scaling &amp; evidence"
+                                                                  Foreground="#B7D1E5" IsExpanded="False">
+                                                            <StackPanel Margin="5,6,4,4">
+                                                                <TextBlock Text="{Binding EngineeringScaleExplanation}"
+                                                                           Foreground="#C2D9EA" FontSize="11"
+                                                                           TextWrapping="Wrap"/>
+                                                                <TextBlock Text="{Binding EvidenceCopyStatusText}"
+                                                                           Foreground="#94B4CC" FontSize="10"
+                                                                           TextTrimming="CharacterEllipsis"
+                                                                           Margin="0,4,0,0"/>
+                                                            </StackPanel>
+                                                        </Expander>
                                                     </StackPanel>
-                                                </Expander>
+                                                </Border>
                                             </StackPanel>
                                         </ScrollViewer>
                                     </Border>
diff --git a/src/ProcessBus.Core/Models/WaveformAutoRangePolicy.cs b/src/ProcessBus.Core/Models/WaveformAutoRangePolicy.cs
new file mode 100644
index 00000000..c8a1277a
--- /dev/null
+++ b/src/ProcessBus.Core/Models/WaveformAutoRangePolicy.cs
@@ -0,0 +1,21 @@
+namespace ProcessBus.Core.Models;
+
+/// <summary>
+/// Screen-only oscilloscope scale guard. A WPF panel is reused across SV streams
+/// and raw-to-nominal unit transitions; old peaks cannot remain authoritative.
+/// No decoded SV samples, phase, RMS, or packet diagnostics are altered.
+/// </summary>
+public static class WaveformAutoRangePolicy
+{
+    public static bool UnitsChanged(string? previousUnit, string? nextUnit) =>
+        !string.Equals(previousUnit, nextUnit, StringComparison.OrdinalIgnoreCase);
+
+    public static bool ShouldReleasePeakHold(double heldPeak, double incomingPeak)
+    {
+        if (!double.IsFinite(heldPeak) || heldPeak <= 0)
+            return true;
+        if (!double.IsFinite(incomingPeak) || incomingPeak <= 0)
+            return false;
+        return incomingPeak >= heldPeak || incomingPeak < heldPeak * 0.25;
+    }
+}
diff --git a/tests/ProcessBus.Tests/WaveformAutoRangePolicyTests.cs b/tests/ProcessBus.Tests/WaveformAutoRangePolicyTests.cs
new file mode 100644
index 00000000..f3f40b07
--- /dev/null
+++ b/tests/ProcessBus.Tests/WaveformAutoRangePolicyTests.cs
@@ -0,0 +1,35 @@
+using ProcessBus.Core.Models;
+using Xunit;
+
+namespace ProcessBus.Tests;
+
+public sealed class WaveformAutoRangePolicyTests
+{
+    [Theory]
+    [InlineData("counts", "V", true)]
+    [InlineData("counts", "A", true)]
+    [InlineData("V", "V", false)]
+    [InlineData("A", "A", false)]
+    [InlineData(null, "V", true)]
+    public void ChangingDisplayUnitReleasesOldScale(string? prior, string? current, bool expected)
+    {
+        Assert.Equal(expected, WaveformAutoRangePolicy.UnitsChanged(prior, current));
+    }
+
+    [Fact]
+    public void RawCountToNominalVoltAndAmpResetImmediately()
+    {
+        Assert.True(WaveformAutoRangePolicy.ShouldReleasePeakHold(104500, 104.5));
+        Assert.True(WaveformAutoRangePolicy.ShouldReleasePeakHold(1810, 1.81));
+    }
+
+    [Fact]
+    public void NormalPeakHoldHoldsSmallFluctuationsAndReleasesTrueAmplitudeChange()
+    {
+        Assert.False(WaveformAutoRangePolicy.ShouldReleasePeakHold(104, 102));
+        Assert.False(WaveformAutoRangePolicy.ShouldReleasePeakHold(104, 50));
+        Assert.True(WaveformAutoRangePolicy.ShouldReleasePeakHold(104, 25));
+        Assert.True(WaveformAutoRangePolicy.ShouldReleasePeakHold(104, 115));
+        Assert.False(WaveformAutoRangePolicy.ShouldReleasePeakHold(104, double.NaN));
+    }
+}