Models/AppConfig.cs

@@ -46,7 +46,7 @@ public class TestParameters
     public int MeasurementCount { get; set; } = 10;
     [Range(5, 300)]
     public int IntervalSeconds { get; set; } = 30;
-    public double PlatinumWireLength { get; set; } = 0.04;
+    public double PlatinumWireLength { get; set; } = 0.056; // 默认 5.6 cm
     public double PlatinumWireDiameter { get; set; } = 0.00006;
     public string ReportOutputPath { get; set; } = "Reports\\";
 
@@ -60,6 +60,18 @@ public class TestParameters
 
     public CalibrationCoefficients CalibrationCoefficients { get; set; } = new();
 
+    // 可选：强制使用固定的物性值，便于测试和校准
+    public bool UseFixedAlpha { get; set; } = false;
+    public double FixedAlpha { get; set; } = 1.4e-7; // m^2/s
+    public bool UseFixedLambda { get; set; } = false;
+    public double FixedLambda { get; set; } = 0.606; // W/(m·K)
+
+
+
+    public double FitStartTime { get; set; } = 0.01;   // 默认0.35秒，避开早期扰动
+    public double FitEndTime { get; set; } = 0.1;
+
+
 
 }
 

ViewModels/D7896ViewModel.cs

@@ -8,7 +8,9 @@ using OxyPlot.Axes;
 using OxyPlot.Series;
 using System;
 using System.Collections.ObjectModel;
+using System.IO;
 using System.Linq;
+using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 using System.Windows;
@@ -87,7 +89,8 @@ public partial class D7896ViewModel : ObservableObject
 
 
     private const double EulerGamma = 0.5772156649;   // 欧拉常数
-    private const double WireRadius = 0.00003;        // 铂丝半径 (0.03 mm)
+    //private const double WireRadius = 0.00003;        // 铂丝半径 (0.03 mm)
+    private const double WireRadius = 0.00010;        // 铂丝半径 (0.03 mm)
     [ObservableProperty] private double _sampleDensity = 1000.0;   // 新增，密度默认值1000 kg/m³（水）
     int samples = 1000; // 1秒 * 1000点/秒
     double heatingDuration = 1;        // 加热时间 0.8 秒（需与您的加热脉冲宽度一致）
@@ -273,46 +276,88 @@ public partial class D7896ViewModel : ObservableObject
                 CurrentMeasurementIndex = i;
                 StatusMessage = $"正在执行第 {i} 次测量...";
 
-                // === 正式加热与采集 ===
+
+
+                // --- 步骤1：基线采集（加热前）---
+                await _th1963Ustd.PrepareBatchAsync(50);
+                await _th1953Ustd.PrepareBatchAsync(50);
+                await Task.WhenAll(_th1963Ustd.TriggerAsync(), _th1953Ustd.TriggerAsync());
+                await Task.Delay(100);
+                double[] ustdBase = await _th1963Ustd.FetchBatchAsync();
+                double[] uptBase = await _th1953Ustd.FetchBatchAsync();
+
+                double dynamicR0 = 2.45; // 默认值
+                if (ustdBase != null && ustdBase.Length > 0 && uptBase != null && uptBase.Length > 0)
+                {
+                    double sumR0 = 0; int cnt = 0;
+                    for (int j = 0; j < ustdBase.Length; j++)
+                    {
+                        if (ustdBase[j] > 0.01 && uptBase[j] > 0.01)
+                        {
+                            sumR0 += uptBase[j] / ustdBase[j];
+                            cnt++;
+                        }
+                    }
+                    if (cnt > 0)
+                    {
+                        dynamicR0 = sumR0 / cnt;
+                        Logger.Log($"基线采集 R0 = {dynamicR0:F6} Ω (有效点数: {cnt})");
+                    }
+                    else
+                    {
+                        Logger.Log("基线采集数据无效（电压过低），使用加热前瞬间点");
+                    }
+                }
+                else
+                {
+                    Logger.Log("基线采集未返回数据，将使用加热段早期点");
+                }
+
+
+
+
+
+
+
+
+
+
+                // --- 步骤2：正式加热采集 ---
                 await _th1963Ustd.PrepareBatchAsync(samples);
                 await _th1953Ustd.PrepareBatchAsync(samples);
 
-                // 启动加热脉冲 (PLC)
                 await _plcService.WriteCoilAsync(_config.PlcRegisterAddresses.StartCommand, true);
-
                 try { await Task.Delay(5, _testCts.Token); } catch (OperationCanceledException) { break; }
 
-                // 触发采集
                 await Task.WhenAll(_th1963Ustd.TriggerAsync(), _th1953Ustd.TriggerAsync());
 
-                // 等待加热结束
                 try { await Task.Delay((int)(heatingDuration * 1000), _testCts.Token); } catch (OperationCanceledException) { break; }
-
-                // 停止加热
                 await _plcService.WriteCoilAsync(_config.PlcRegisterAddresses.StartCommand, false);
 
-                // 等待采集完成
                 int remainingMs = (int)((totalDuration - heatingDuration) * 1000) + 100;
                 try { await Task.Delay(remainingMs, _testCts.Token); } catch (OperationCanceledException) { break; }
 
-                // 获取采集数据
                 double[] ustd = await _th1963Ustd.FetchBatchAsync();
                 double[] upt = await _th1953Ustd.FetchBatchAsync();
 
-
-                // 动态计算初始电阻 R0（取第2~11点，跳过初始扰动）
-                double sumR0 = 0;
-                int r0Cnt = 0;
-                for (int j = 2; j < Math.Min(12, ustd.Length); j++)
+                if (dynamicR0 == 2.45) // 仍为默认值，说明基线无效
                 {
-                    if (ustd[j] > 0.01 && upt[j] > 0.01)
+                    double sumR0 = 0; int cnt = 0;
+                    // 改用第 10 到 19 点（共10个点），避开前10个点的干扰
+                    for (int j = 10; j < Math.Min(20, ustd.Length); j++)
                     {
-                        sumR0 += upt[j] / ustd[j];
-                        r0Cnt++;
+                        if (ustd[j] > 0.01 && upt[j] > 0.01)
+                        {
+                            sumR0 += upt[j] / ustd[j];
+                            cnt++;
+                        }
+                    }
+                    if (cnt > 0)
+                    {
+                        dynamicR0 = sumR0 / cnt;
+                        Logger.Log($"使用加热段第10~19点计算 R0 = {dynamicR0:F6} Ω");
                     }
                 }
-                double dynamicR0 = r0Cnt > 0 ? sumR0 / r0Cnt : 2.34;
-                Logger.Log($"动态计算 R0 = {dynamicR0:F6} Ω (有效点数: {r0Cnt})");
 
 
 
@@ -398,7 +443,6 @@ public partial class D7896ViewModel : ObservableObject
 
 
 
-
     private (double lambda, double alpha, double[] deltaT, List<DataPoint> coolingPoints) ComputeThermalProperties(
         double[] upt, double[] ustd, double[] time, double initialResistance, double bathTemp)
     {
@@ -406,12 +450,14 @@ public partial class D7896ViewModel : ObservableObject
         double[] deltaT = new double[n];
         double[] ptResistance = new double[n];
         double[] current = new double[n];
+        double tStart = _config.TestParameters.FitStartTime;
+        double tEnd = _config.TestParameters.FitEndTime;
 
-        // 1. 瞬时计算
+        // 1. 瞬时计算（先用传入的 initialResistance）
         for (int i = 0; i < n; i++)
         {
             current[i] = ustd[i] / StandardResistor;
-            if (current[i] > 0.001)  // 降低阈值到 1mA
+            if (current[i] > 0.001)
             {
                 ptResistance[i] = upt[i] / current[i];
                 deltaT[i] = (ptResistance[i] - initialResistance) / (AlphaPt * initialResistance);
@@ -423,7 +469,7 @@ public partial class D7896ViewModel : ObservableObject
             }
         }
 
-        // 1.5 滑动平均平滑（窗口5）
+        // 滑动平均平滑（窗口5）
         double[] smoothDeltaT = new double[n];
         for (int i = 0; i < n; i++)
         {
@@ -435,22 +481,16 @@ public partial class D7896ViewModel : ObservableObject
             smoothDeltaT[i] = cnt > 0 ? sum / cnt : double.NaN;
         }
 
-        // 2. 寻找温升峰值点（使用平滑后的数据）
-        int peakIdx = 5;
+        // 寻找温升峰值点
         double maxDeltaT = 0;
         for (int i = 5; i < n; i++)
         {
             if (!double.IsNaN(smoothDeltaT[i]) && smoothDeltaT[i] > maxDeltaT)
-            {
                 maxDeltaT = smoothDeltaT[i];
-                peakIdx = i;
-            }
         }
         Logger.Log($"最大温升 = {maxDeltaT:F4} ℃");
 
-        // 3. 固定时间窗口（0.1 ~ 0.8 秒），避开初始扰动和冷却段
-        double tStart = 0.15;
-        double tEnd = 0.4;
+        // 拟合窗口
         int startIdx = FindIndex(time, tStart);
         int endIdx = FindIndex(time, tEnd);
         if (startIdx < 0) startIdx = 5;
@@ -458,13 +498,12 @@ public partial class D7896ViewModel : ObservableObject
         if (endIdx <= startIdx) endIdx = Math.Min(startIdx + 50, n - 1);
         Logger.Log($"拟合窗口: startIdx={startIdx}, endIdx={endIdx}, 点数={endIdx - startIdx + 1}");
 
-
-
-
-        // 4. 收集拟合点
+        // 收集拟合点
         var points = new List<DataPoint>();
         for (int i = startIdx; i <= endIdx; i++)
         {
+            if (i <= startIdx + 5)  // 只打印前5个点
+                Logger.Log($"i={i}, time={time[i]:F6}, smoothDeltaT={smoothDeltaT[i]:F6}, deltaT={deltaT[i]:F6}");
             if (!double.IsNaN(smoothDeltaT[i]) && smoothDeltaT[i] > 0 && time[i] > 0)
                 points.Add(new DataPoint(Math.Log(time[i]), smoothDeltaT[i]));
         }
@@ -482,35 +521,41 @@ public partial class D7896ViewModel : ObservableObject
             return (0, 0, deltaT, new List<DataPoint>());
         }
 
+        // 打印前10个拟合点
         foreach (var p in points.Take(10))
             Logger.Log($"ln(t)={p.X:F4}, ΔT={p.Y:F4}");
 
-
-
-
-        // 5. 计算功率
-        double sumPower = 0;
-        int validCount = 0;
+        // 计算功率密度
+        double sumI = 0, sumR = 0;
+        int cntI = 0, cntR = 0;
         for (int i = startIdx; i <= endIdx; i++)
         {
-            if (!double.IsNaN(ptResistance[i]))
-            {
-                sumPower += current[i] * current[i] * ptResistance[i];
-                validCount++;
-            }
+            if (!double.IsNaN(current[i]) && Math.Abs(current[i]) > 1e-12) { sumI += current[i]; cntI++; }
+            if (!double.IsNaN(ptResistance[i]) && ptResistance[i] > 1e-12) { sumR += ptResistance[i]; cntR++; }
         }
-        if (validCount == 0) return (0, 0, deltaT, new List<DataPoint>());
-        double avgPower = sumPower / validCount;
-        double wireLength = _config.TestParameters.PlatinumWireLength;
-        double powerPerLength = avgPower / wireLength;
+        if (cntI == 0 || cntR == 0) return (0, 0, deltaT, new List<DataPoint>());
+        double avgCurrent = sumI / cntI;
+        double avgResistance = sumR / cntR;
+        double wireLength = Math.Max(1e-12, _config.TestParameters.PlatinumWireLength);
+        double powerPerLength = (avgCurrent * avgCurrent * avgResistance) / wireLength;
 
         double lambda = powerPerLength / (4 * Math.PI * slope);
-        Logger.Log($"功率密度 = {powerPerLength:F3} W/m, 斜率 B = {slope:F5}");
+        if (_config.TestParameters.UseFixedLambda)
+        {
+            lambda = _config.TestParameters.FixedLambda;
+            Logger.Log($"使用固定 lambda={lambda:F6} W/(m·K)");
+        }
+        Logger.Log($"constantCurrent(avg)={avgCurrent:E6} A, avgResistance={avgResistance:F6} Ω, powerPerLength={powerPerLength:E6} W/m, 斜率 B = {slope:F5}");
 
-        // 6. α 计算
+        // 计算热扩散率
         double exponent = intercept / slope + EulerGamma;
         if (exponent > 30) exponent = 30;
         double alpha = (WireRadius * WireRadius / 4.0) * Math.Exp(exponent);
+        if (_config.TestParameters.UseFixedAlpha)
+        {
+            alpha = _config.TestParameters.FixedAlpha;
+            Logger.Log($"使用固定 alpha={alpha:E6} m²/s");
+        }
         if (alpha <= 0 || double.IsNaN(alpha) || alpha > 1e-5)
         {
             Logger.Log($"警告：α 计算异常 ({alpha:E})，数据可能不可靠");
@@ -526,11 +571,27 @@ public partial class D7896ViewModel : ObservableObject
             if (!double.IsNaN(deltaT[i]) && deltaT[i] > 0.01)
                 coolingPoints.Add(new DataPoint(time[i], deltaT[i]));
 
+        // 导出CSV
+        try
+        {
+            string tmp = Path.GetTempPath();
+            string baseName = $"measure_{SampleId}_{DateTime.Now:yyyyMMdd_HHmmss}_{CurrentMeasurementIndex}";
+            string dataPath = Path.Combine(tmp, baseName + ".csv");
+            ExportMeasurementCsv(dataPath, time, ustd, upt, deltaT, startIdx, endIdx);
+            Logger.Log($"已导出测量数据 CSV: {dataPath}");
+
+            string winPath = Path.Combine(tmp, baseName + "_windows.csv");
+            ExportCandidateWindowsCsv(winPath, time, deltaT, startIdx, endIdx);
+            Logger.Log($"已导出候选拟合窗 CSV: {winPath}");
+        }
+        catch (Exception ex)
+        {
+            Logger.Log($"导出CSV失败: {ex.Message}");
+        }
+
         return (lambda, alpha, deltaT, coolingPoints);
     }
 
-
-
     /// <summary>
     /// 最小二乘法线性回归，返回 (斜率, 截距)
     /// </summary>
@@ -566,6 +627,34 @@ public partial class D7896ViewModel : ObservableObject
         return timeArray.Length - 1;
     }
 
+    private void ExportMeasurementCsv(string path, double[] time, double[] ustd, double[] upt, double[] deltaT, int fitStart, int fitEnd)
+    {
+        using var sw = new StreamWriter(path, false, Encoding.UTF8);
+        sw.WriteLine("index,time,U_std,U_pt,deltaT,fitWindow");
+        int n = Math.Min(Math.Min(time.Length, ustd.Length), deltaT.Length);
+        for (int i = 0; i < n; i++)
+        {
+            bool inFit = (i >= fitStart && i <= fitEnd);
+            sw.WriteLine($"{i},{time[i]:F6},{ustd[i]:F6},{upt[i]:F6},{(double.IsNaN(deltaT[i])?0:deltaT[i]):F6},{(inFit?1:0)}");
+        }
+    }
+
+    private void ExportCandidateWindowsCsv(string path, double[] time, double[] deltaT, int startIdx, int endIdx)
+    {
+        using var sw = new StreamWriter(path, false, Encoding.UTF8);
+        sw.WriteLine("s,e,t_start,t_end,meanDelta");
+        int n = time.Length;
+        int minPts = 10;
+        for (int s = startIdx; s <= endIdx - minPts; s++)
+        {
+            for (int e = s + minPts - 1; e <= endIdx; e++)
+            {
+                double mean = deltaT.Skip(s).Take(e - s + 1).Where(x => !double.IsNaN(x)).DefaultIfEmpty(0).Average();
+                sw.WriteLine($"{s},{e},{time[s]:F6},{time[e]:F6},{mean:F6}");
+            }
+        }
+    }
+
     ///// <summary>
     ///// 最小二乘法拟合斜率 (X轴为横坐标，Y轴为纵坐标) — 用于加热段 ln(t) vs ΔT
     ///// </summary>

ViewModels/MeasurementResult.cs

@@ -12,7 +12,7 @@ public partial class MeasurementResult : ObservableObject
     private double _thermalConductivity; // W/m·K
 
     [ObservableProperty]
-    private double _thermalDiffusivity;  // ×10⁻⁶ m²/s
+    private double _thermalDiffusivity;  // m²/s
 
     [ObservableProperty]
     private double _specificHeatCapacity;  // 比热容 J/(kg·K)
@@ -50,11 +50,12 @@ public partial class MeasurementResult : ObservableObject
 
     public void CalculateVhc()
     {
-        Debug.WriteLine($"[MeasurementResult] 计算体积热容 - 热导率: {ThermalConductivity} W/(m·K), 热扩散率: {ThermalDiffusivity} ×10⁻⁶ m²/s");
+        Debug.WriteLine($"[MeasurementResult] 计算体积热容 - 热导率: {ThermalConductivity} W/(m·K), 热扩散率: {ThermalDiffusivity} m²/s");
 
         if (ThermalDiffusivity > 0)
         {
-            VolumetricHeatCapacity = ThermalConductivity / (ThermalDiffusivity * 1e-6) / 1000.0;
+            // VHC (kJ/(m³·K)) = (λ / α) / 1000
+            VolumetricHeatCapacity = ThermalConductivity / ThermalDiffusivity / 1000.0;
             Debug.WriteLine($"[MeasurementResult] 计算得到体积热容: {VolumetricHeatCapacity} kJ/(m³·K)");
         }
         else

appsettings.json

@@ -25,8 +25,9 @@
   "TestParameters": {
     "MeasurementCount": 10,
     "IntervalSeconds": 30,
-    "PlatinumWireLength": 0.07, //铂丝长度（单位：米）
-    "PlatinumWireDiameter": 0.00006,
+    //"PlatinumWireLength": 0.056, //铂丝长度（单位：米）
+    "PlatinumWireLength": 0.41, //铂丝长度（单位：米）
+    "PlatinumWireDiameter": 0.000025,
     "ReportOutputPath": "Reports\\",
     "DefaultSampleVolume": 40.0,
     "DefaultPressure": 0.0,