From b009fabfdbde7a8d044982ae1c8a7ddfbf4fc184 Mon Sep 17 00:00:00 2001
From: "GukSang.Jin" <guksang_chen@163.com>
Date: Fri, 22 May 2026 15:33:31 +0800
Subject: [PATCH] =?UTF-8?q?=E6=9B=B4=E6=96=B0?=
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Content-Type: text/plain; charset=UTF-8
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---
 .../SmokeDensitySettingsViewModel.cs          | 72 ++++++++++++++++---
 1 file changed, 64 insertions(+), 8 deletions(-)

diff --git a/ConeCalorimeter/ViewModels/SmokeDensitySettingsViewModel.cs b/ConeCalorimeter/ViewModels/SmokeDensitySettingsViewModel.cs
index 9be537a..767cc8e 100644
--- a/ConeCalorimeter/ViewModels/SmokeDensitySettingsViewModel.cs
+++ b/ConeCalorimeter/ViewModels/SmokeDensitySettingsViewModel.cs
@@ -13,12 +13,17 @@ public sealed class SmokeDensitySettingsViewModel : PageViewModel
     private const ushort AbsorbanceRegister = 120;
     private const double AbsorbanceMinimum = 0;
     private const double AbsorbanceMaximum = 100;
+    private const double AbsorbanceStableTolerance = 0.25;
+    private const int AbsorbanceStableReadCount = 2;
 
     private readonly Action _closeAction;
     private readonly ITcpDeviceConnectionService _tcpDeviceConnectionService;
     private readonly DispatcherTimer _refreshTimer;
     private readonly HashSet<ushort> _loggedFloatDiagnostics = [];
     private readonly HashSet<ushort> _loggedInvalidFloatDiagnostics = [];
+    private double? _stableAbsorbance;
+    private double? _pendingAbsorbance;
+    private int _pendingAbsorbanceReadCount;
     private string _absorbanceText = "";
     private string _lastCalibration = "待校准";
 
@@ -90,34 +95,85 @@ public sealed class SmokeDensitySettingsViewModel : PageViewModel
 
     private void RefreshDeviceValues()
     {
-        AbsorbanceText = ReadRangedFloatText(
+        if (!TryReadRangedFloatValue(
             "Absorbance",
             AbsorbanceRegister,
             AbsorbanceMinimum,
             AbsorbanceMaximum,
-            "0.00");
+            out var value))
+        {
+            if (!_stableAbsorbance.HasValue)
+            {
+                AbsorbanceText = string.Empty;
+            }
+
+            return;
+        }
+
+        if (TryUpdateStableAbsorbance(value, out var stableValue))
+        {
+            AbsorbanceText = stableValue.ToString("0.00", CultureInfo.InvariantCulture);
+        }
     }
 
-    private string ReadRangedFloatText(
+    private bool TryReadRangedFloatValue(
         string label,
         ushort registerAddress,
         double minimum,
         double maximum,
-        string format)
+        out double value)
     {
+        value = double.NaN;
+
         if (!_tcpDeviceConnectionService.TryReadFloatValues(registerAddress, out var result))
         {
-            return string.Empty;
+            return false;
         }
 
-        if (!ModbusFloatSelector.TrySelectRangedFloat(result, minimum, maximum, out var byteOrder, out var value, out var matchCount))
+        if (!ModbusFloatSelector.TrySelectRangedFloat(result, minimum, maximum, out var byteOrder, out var selectedValue, out var matchCount))
         {
             LogFloatDiagnostic(label, registerAddress, result, null, matchCount);
-            return string.Empty;
+            return false;
         }
 
         LogFloatDiagnostic(label, registerAddress, result, byteOrder, matchCount);
-        return NormalizeDisplayValue(value).ToString(format, CultureInfo.InvariantCulture);
+        value = NormalizeDisplayValue(selectedValue);
+        return true;
+    }
+
+    private bool TryUpdateStableAbsorbance(double value, out double stableValue)
+    {
+        stableValue = _stableAbsorbance ?? value;
+
+        if (_stableAbsorbance.HasValue
+            && Math.Abs(value - _stableAbsorbance.Value) <= AbsorbanceStableTolerance)
+        {
+            _pendingAbsorbance = null;
+            _pendingAbsorbanceReadCount = 0;
+            stableValue = _stableAbsorbance.Value;
+            return true;
+        }
+
+        if (!_pendingAbsorbance.HasValue
+            || Math.Abs(value - _pendingAbsorbance.Value) > AbsorbanceStableTolerance)
+        {
+            _pendingAbsorbance = value;
+            _pendingAbsorbanceReadCount = 1;
+            return false;
+        }
+
+        _pendingAbsorbanceReadCount++;
+
+        if (_pendingAbsorbanceReadCount < AbsorbanceStableReadCount)
+        {
+            return false;
+        }
+
+        _stableAbsorbance = value;
+        _pendingAbsorbance = null;
+        _pendingAbsorbanceReadCount = 0;
+        stableValue = value;
+        return true;
     }
 
     private void LogFloatDiagnostic(