From 8a6458071ae7a5642292557aa7dcf83f564d64aa Mon Sep 17 00:00:00 2001
From: "GukSang.Jin" <guksang_chen@163.com>
Date: Thu, 7 May 2026 16:44:36 +0800
Subject: [PATCH] =?UTF-8?q?=E6=9B=B4=E6=96=B0?=
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---
 ConeCalorimeter/Models/RealtimeDataRecord.cs  | 11 +++---
 ConeCalorimeter/Models/RealtimeSnapshot.cs    |  1 +
 .../Services/ExperimentDataService.cs         | 36 +++++++++++++++++--
 .../Services/ModbusRealtimeDataService.cs     |  1 +
 4 files changed, 42 insertions(+), 7 deletions(-)

diff --git a/ConeCalorimeter/Models/RealtimeDataRecord.cs b/ConeCalorimeter/Models/RealtimeDataRecord.cs
index b0c8cec..c7c82b8 100644
--- a/ConeCalorimeter/Models/RealtimeDataRecord.cs
+++ b/ConeCalorimeter/Models/RealtimeDataRecord.cs
@@ -22,10 +22,13 @@ public sealed record RealtimeDataRecord(
     double CurrentMass,
     double InitialMass,
     double MassLoss,
+    double MassLossRate,
     int IgnitionSeconds,
     int TestSeconds,
     double TotalSmoke)
 {
+    private const double DefaultIrradiatedAreaSquareMeters = 0.01;
+
     public static RealtimeDataRecord FromSnapshot(RealtimeSnapshot snapshot)
     {
         return new RealtimeDataRecord(
@@ -50,19 +53,17 @@ public sealed record RealtimeDataRecord(
             snapshot.CurrentMass,
             snapshot.InitialMass,
             snapshot.MassLoss,
+            snapshot.MassLossRate,
             snapshot.IgnitionSeconds,
             snapshot.TestSeconds,
             snapshot.TotalSmoke);
     }
 
-    public double MassLossRate =>
-        double.IsFinite(MassLoss) && TestSeconds > 0 ? MassLoss / TestSeconds : double.NaN;
-
     public double HeatReleaseRateKw =>
-        double.IsFinite(HeatReleaseRate) ? HeatReleaseRate * 1000 : double.NaN;
+        double.IsFinite(HeatReleaseRate) ? HeatReleaseRate : double.NaN;
 
     public double EffectiveHeatOfCombustion =>
         double.IsFinite(HeatReleaseRate) && double.IsFinite(MassLossRate) && MassLossRate > 0
-            ? HeatReleaseRate / MassLossRate * 10
+            ? HeatReleaseRate * DefaultIrradiatedAreaSquareMeters / MassLossRate
             : double.NaN;
 }
diff --git a/ConeCalorimeter/Models/RealtimeSnapshot.cs b/ConeCalorimeter/Models/RealtimeSnapshot.cs
index ae92312..9912a80 100644
--- a/ConeCalorimeter/Models/RealtimeSnapshot.cs
+++ b/ConeCalorimeter/Models/RealtimeSnapshot.cs
@@ -21,6 +21,7 @@ public sealed record RealtimeSnapshot(
     double CurrentMass,
     double InitialMass,
     double MassLoss,
+    double MassLossRate,
     int IgnitionSeconds,
     int TestSeconds,
     double TotalSmoke);
diff --git a/ConeCalorimeter/Services/ExperimentDataService.cs b/ConeCalorimeter/Services/ExperimentDataService.cs
index 3caf0e1..940d8fa 100644
--- a/ConeCalorimeter/Services/ExperimentDataService.cs
+++ b/ConeCalorimeter/Services/ExperimentDataService.cs
@@ -12,6 +12,8 @@ public sealed class ExperimentDataService : IExperimentDataService
     private readonly DispatcherTimer _timer;
     private readonly DateTime _startedAt = DateTime.Now;
     private double? _initialMass;
+    private double? _previousMass;
+    private int? _previousMassSeconds;
     private double _accumulatedTotalHeatRelease;
     private double _accumulatedTotalSmoke;
     private int? _lastAccumulationSeconds;
@@ -139,7 +141,8 @@ public sealed class ExperimentDataService : IExperimentDataService
             return snapshot with
             {
                 InitialMass = _initialMass ?? double.NaN,
-                MassLoss = double.NaN
+                MassLoss = double.NaN,
+                MassLossRate = double.NaN
             };
         }
 
@@ -151,17 +154,46 @@ public sealed class ExperimentDataService : IExperimentDataService
         var massLoss = _initialMass.HasValue && double.IsFinite(snapshot.CurrentMass)
             ? _initialMass.Value - snapshot.CurrentMass
             : double.NaN;
+        var massLossRate = CalculateMassLossRate(snapshot);
 
         return snapshot with
         {
             InitialMass = _initialMass ?? double.NaN,
-            MassLoss = massLoss
+            MassLoss = massLoss,
+            MassLossRate = massLossRate
         };
     }
 
+    private double CalculateMassLossRate(RealtimeSnapshot snapshot)
+    {
+        if (snapshot.TestSeconds < 0 || !double.IsFinite(snapshot.CurrentMass))
+        {
+            return double.NaN;
+        }
+
+        if (!_previousMass.HasValue || !_previousMassSeconds.HasValue)
+        {
+            _previousMass = snapshot.CurrentMass;
+            _previousMassSeconds = snapshot.TestSeconds;
+            return double.NaN;
+        }
+
+        var deltaSeconds = snapshot.TestSeconds - _previousMassSeconds.Value;
+        var deltaMass = _previousMass.Value - snapshot.CurrentMass;
+
+        _previousMass = snapshot.CurrentMass;
+        _previousMassSeconds = snapshot.TestSeconds;
+
+        return deltaSeconds > 0 && deltaMass >= 0
+            ? deltaMass / deltaSeconds
+            : double.NaN;
+    }
+
     private void ResetComputedState()
     {
         _initialMass = null;
+        _previousMass = null;
+        _previousMassSeconds = null;
         _accumulatedTotalHeatRelease = 0;
         _accumulatedTotalSmoke = 0;
         _lastAccumulationSeconds = null;
diff --git a/ConeCalorimeter/Services/ModbusRealtimeDataService.cs b/ConeCalorimeter/Services/ModbusRealtimeDataService.cs
index daaa9b5..244f6e4 100644
--- a/ConeCalorimeter/Services/ModbusRealtimeDataService.cs
+++ b/ConeCalorimeter/Services/ModbusRealtimeDataService.cs
@@ -54,6 +54,7 @@ public sealed class ModbusRealtimeDataService : IRealtimeDataService
             CurrentMass: ReadFloatOrEmpty(CurrentMassRegister),
             InitialMass: double.NaN,
             MassLoss: double.NaN,
+            MassLossRate: double.NaN,
             IgnitionSeconds: ReadInt16OrEmpty(IgnitionSecondsRegister),
             TestSeconds: ReadInt16OrEmpty(TestSecondsRegister),
             TotalSmoke: double.NaN);