Ship alarm system includes engine room detection alarm, fire detection alarm and cargo compartment detection alarm. Among them, the engine room detection and alarm system collects the pressure, temperature, speed and other parameters of the main engine and auxiliary engine, and converts them into analog or digital output through the main controller. If the output value exceeds the set value, an audible and visual alarm signal will be generated, so that the personnel on duty can handle the abnormal situation in time and restore the equipment to normal state. The cargo hold detection and alarm system outputs signals by detecting the gas condition in the cargo hold. The fire detection and alarm system outputs signals by measuring the temperature or smoke concentration in the space around the sensor.

The alarm signals in the detection and alarm device of ship engine room are usually divided into switch alarm and analog alarm. Switch alarm is divided into liquid level switch, pressure switch, temperature switch, electrical equipment switch, frequency speed switch, etc. Check the quality of the level switch sensor before installing it. The method is to detect its on-off state with a multimeter, and send a signal to the main controller by simulating the switch value to judge the quality of the sensor and the control box. The detection method of temperature switch value is to determine the set value first, and then adjust the control value of the controller with the set value of eucalyptus. The detection of pressure switch value should first find out the alarm setting value, and then adjust it to the alarm value according to the setting value. The manual pump pressurizes the pressure sensor, uses a multimeter to measure the working state of the pressure switch, and simulates the pressure switch to send a signal to the main controller to judge the quality of the main controller. The frequency speed sensor mainly checks whether the frequency signal speed device moves, and uses a multimeter to detect whether it moves when it reaches the set value.