diff --git a/src/src/main/java/com/my/graphiteDigesterBg/resource/ResHeatingTubeRackSlotManager.java b/src/src/main/java/com/my/graphiteDigesterBg/resource/ResHeatingTubeRackSlotManager.java
index 666f269..c7b8cfb 100644
--- a/src/src/main/java/com/my/graphiteDigesterBg/resource/ResHeatingTubeRackSlotManager.java
+++ b/src/src/main/java/com/my/graphiteDigesterBg/resource/ResHeatingTubeRackSlotManager.java
@@ -12,6 +12,8 @@ public class ResHeatingTubeRackSlotManager extends DiResourceManagerBase {
     private final List<ResHeatingTubeRackSlot> slots;
     // error slot index
     private Integer errorSlotIndex;
+    // temperature refresh timer
+    private Timer temperatureRefreshTimer;
 
     // constructor
     public ResHeatingTubeRackSlotManager() {
@@ -28,10 +30,12 @@ public class ResHeatingTubeRackSlotManager extends DiResourceManagerBase {
         this.errorSlotIndex = this.getDevice().getEnv().getProperty("app.errorSlotIndex",Integer.class);
         assert Objects.nonNull(this.errorSlotIndex);
         this.slots.get(this.errorSlotIndex).setupAsErrorSlot();
+    }
 
-        // start a timer task to refresh slot temperature every 5 seconds
-        var timer = new Timer();
-        timer.schedule(new TimerTask() {
+    // start temperature refresh
+    public void startTemperatureRefresh() {
+        this.temperatureRefreshTimer = new Timer();
+        this.temperatureRefreshTimer.schedule(new TimerTask() {
             @Override
             public void run() {
                 ResHeatingTubeRackSlotManager.this.refreshSlotTemperature();
@@ -39,6 +43,11 @@ public class ResHeatingTubeRackSlotManager extends DiResourceManagerBase {
         }, 0, 5000);
     }
 
+    // stop temperature refresh
+    public void stopTemperatureRefresh() {
+        this.temperatureRefreshTimer.cancel();
+    }
+
     // refresh slot temperature
     public void refreshSlotTemperature() {
         var registers = this.getDevice().getRegisters();
diff --git a/src/src/main/java/com/my/graphiteDigesterBg/task/TaskSampleAdd.java b/src/src/main/java/com/my/graphiteDigesterBg/task/TaskSampleAdd.java
index 3022e53..37942a1 100644
--- a/src/src/main/java/com/my/graphiteDigesterBg/task/TaskSampleAdd.java
+++ b/src/src/main/java/com/my/graphiteDigesterBg/task/TaskSampleAdd.java
@@ -37,9 +37,12 @@ public class TaskSampleAdd extends DiTaskBase {
         liquidPlateMotor.moveTo("LiquidPlatePlaceTubeRack");
         // 等待用户添加完成
         this.waitForUserAction();
+        // 关闭设备门
+        doorMotor.moveToIO(1, 1);
         if ( "canceled".equals(this.addStatus) ) {
             slot.unlock();
             this.setStatus(TaskStatus.FINISHED);
+            return;
         }
 
         var moveMoveTubeRackFromLiquidPlateToHeatPlate = new MoveMoveTubeRackFromLiquidPlateToHeatPlate();
@@ -47,8 +50,6 @@ public class TaskSampleAdd extends DiTaskBase {
         moveMoveTubeRackFromLiquidPlateToHeatPlate.setDevice(this.getDevice());
         moveMoveTubeRackFromLiquidPlateToHeatPlate.run();
 
-        // 关闭设备门
-        doorMotor.moveToIO(1, 1);
         this.setStatus(TaskStatus.FINISHED);
     }