Five Key Points to Easily Determine Whether a Toxic Gas Alarm Is Malfunctioning
For the troubleshooting of toxic gas alarms, we first need to know the location and cause of the malfunction. Generally speaking, there are several methods to determine whether a toxic gas alarm has malfunctioned, including:
1. Comparison method:
Two toxic gas alarms of the same model are required, and one of them is in normal operation. The specific method is to operate the faulty instrument and the normal instrument under the same conditions, then detect the signals of some points and compare the two sets of signals measured. If there are differences, it can be concluded that the fault lies here. This method requires maintenance personnel to have considerable knowledge and skills.
2. Shoulder riding technique:
The shoulder riding method is also known as the parallel method. Install a good IC chip on top of the chip to be inspected, or connect good components (resistors, capacitors, diodes, transistors, etc.) in parallel with the components to be inspected, maintaining good contact. If the fault is caused by an open circuit or poor contact inside the device, this method can be used to eliminate it.
3. Hand tapping method:
It is common to encounter the phenomenon of instruments running intermittently, which is mostly caused by poor contact or virtual soldering. For this situation, tapping and hand pressure methods can be used. The so-called "tapping" refers to gently tapping the plug-in board or component with a small rubber mallet or other tapping object on the possible faulty part to see if it will cause errors or shutdown faults. The so-called 'manual pressure' refers to the process of turning off the power and then manually pressing the plugged components, plugs, and sockets back firmly when a fault occurs, and then turning on the machine to see if it can eliminate the fault. If it is found that knocking the casing once is normal, but then knocking it again is not normal, you can first re plug all the connectors and try again. If it is troublesome and unsuccessful, you have to find another way.
4. Heating and cooling method:
The instrument will malfunction if it works for a long time or when the working environment temperature is high in summer. After shutting down and checking, it will work normally. After stopping for a period of time and then turning it back on, the malfunction will occur again after a while. This phenomenon is caused by poor performance of individual ICs or components, and the high-temperature characteristic parameters cannot meet the requirements of the indicators. To identify the cause of the malfunction, the temperature rise and fall method can be used. The so-called cooling refers to using cotton fibers to wipe anhydrous alcohol on the possible faulty area when a malfunction occurs, to cool it down and observe whether the malfunction is eliminated. The so-called temperature rise refers to artificially raising the ambient temperature, such as placing an electric soldering iron close to the suspicious area (be careful not to raise the temperature too high and damage normal components) to see if a fault occurs.
5. Substitution method:
Require two instruments of the same model or sufficient spare parts. Replace a good spare part with the same component on the faulty machine and see if the fault is eliminated.
