diff --git a/backend/sitemanagement/models.py b/backend/sitemanagement/models.py
index 5bc7952..8fe2556 100644
--- a/backend/sitemanagement/models.py
+++ b/backend/sitemanagement/models.py
@@ -4,7 +4,7 @@ from decimal import Decimal
 
 class Multiplexor(models.Model):
     """Устройство-мультиплексор"""
-    name = models.CharField(max_length=50, unique=True)  
+    name = models.CharField(max_length=50, unique=True)
     ip = models.GenericIPAddressField(null=True, blank=True)
     subnet = models.GenericIPAddressField(null=True, blank=True)
     gateway = models.GenericIPAddressField(null=True, blank=True)
@@ -19,14 +19,14 @@ class Channel(models.Model):
     multiplexor = models.ForeignKey(Multiplexor, on_delete=models.CASCADE, related_name="channels")
     number = models.PositiveSmallIntegerField()  # CH-1 ... CH-14
     # для "полканалов" можно использовать дробное значение (1, 1.5, 2, ...)
-    position = models.DecimalField(max_digits=4, decimal_places=1, default=Decimal("1.0")) 
+    position = models.DecimalField(max_digits=4, decimal_places=1, default=Decimal("1.0"))
 
     class Meta:
         unique_together = ("multiplexor", "number", "position")
 
     def __str__(self):
         return f"{self.multiplexor.name} - CH{self.number} ({self.position})"
-    
+
 
 class SensorType(models.Model):
     """Тип датчика: GA, PE, GLE"""
@@ -34,6 +34,10 @@ class SensorType(models.Model):
     name = models.CharField(max_length=100)
     description = models.TextField(blank=True, null=True)
 
+    # пороговые значения для всех сенсоров этого типа
+    min_value = models.DecimalField(max_digits=12, decimal_places=4, null=True, blank=True)
+    max_value = models.DecimalField(max_digits=12, decimal_places=4, null=True, blank=True)
+
     def __str__(self):
         return self.code
 
@@ -44,7 +48,6 @@ class SignalFormat(models.Model):
     code = models.CharField(max_length=50)  # например "4-20мА", "VW f<1600Hz", "NTC R>250Ohm"
     unit = models.CharField(max_length=20, blank=True, null=True)  # °C, мкм/м, мм и т.п.
     conversion_rule = models.CharField(max_length=255, blank=True, null=True)
-    # можно хранить Python-путь к функции конвертации, например "sensors.convert.ga_current_to_angle"
 
     class Meta:
         unique_together = ("sensor_type", "code")
@@ -80,4 +83,32 @@ class Metric(models.Model):
         ]
 
     def __str__(self):
-        return f"{self.timestamp} {self.sensor} = {self.value} {self.sensor.signal_format.unit if self.sensor.signal_format else ''}"
\ No newline at end of file
+        return f"{self.timestamp} {self.sensor} = {self.value} {self.sensor.signal_format.unit if self.sensor.signal_format else ''}"
+
+
+class Alert(models.Model):
+    """Тревоги по метрикам"""
+    sensor = models.ForeignKey(Sensor, on_delete=models.CASCADE, related_name="alerts")
+    metric = models.ForeignKey(Metric, on_delete=models.CASCADE, related_name="alerts")
+    sensor_type = models.ForeignKey(SensorType, on_delete=models.CASCADE, related_name="alerts")
+    message = models.CharField(max_length=255)
+    severity = models.CharField(
+        max_length=20,
+        choices=[
+            ("warning", "Warning"),
+            ("critical", "Critical"),
+        ],
+        default="warning"
+    )
+    created_at = models.DateTimeField(auto_now_add=True)
+    resolved = models.BooleanField(default=False)
+
+    class Meta:
+        indexes = [
+            models.Index(fields=["created_at"]),
+            models.Index(fields=["sensor"]),
+            models.Index(fields=["sensor_type"]),
+        ]
+
+    def __str__(self):
+        return f"ALERT {self.sensor} @ {self.metric.timestamp}: {self.message}"
\ No newline at end of file