NegativePressure

Mock<ISensor> mockSensor = new Mock<ISensor>();

            mockSensor.Setup(s => s.PopNextPressurePsiValue()).Returns(-10);

            Type alarmType = typeof(Alarm);

            Alarm classInstance = (Alarm)Activator.CreateInstance(alarmType);
            FieldInfo sensor = alarmType.GetField("_sensor", BindingFlags.Instance | BindingFlags.NonPublic);
            MethodInfo checkMethod = alarmType.GetMethod("Check", BindingFlags.Instance | BindingFlags.Public);

            sensor.SetValue(classInstance, mockSensor.Object);

            Assert.Throws<ArgumentOutOfRangeException>(() => classInstance.Check());