Fault Detection of the Four-in-One Gas Detector
The four-in-one gas detector is a flexibly configurable single-gas or multi-gas detector. It can be equipped with an oxygen sensor, a combustible gas sensor, and toxic gas sensors, or optionally four gas sensors, or an optional single gas sensor. The four-in-one gas detector features a very clear large liquid crystal display screen with backlight illumination, and audible, visual and vibration alarm prompts, ensuring that dangerous gases can be detected and operators can be promptly alerted for prevention even in extremely adverse working environments.
The principle of the detection part of the four-in-one gas detector is that when the concentration of the detected combustible gas exceeds the specified limit, the amplified bridge output voltage and the circuit detection setting voltage, through a voltage comparator, make the square wave generator output a set of square wave signals to control the audible and visual detection circuits. The buzzer emits continuous sounds and the light-emitting diodes flash to send out detection signals. From the principle of the four-in-one gas detector, it can be seen that if there is electromagnetic interference, it will affect the detected signals and cause data deviations; if there are collisions or vibrations that result in equipment open circuits, the detection will fail; if the environment is too humid or the equipment gets water ingress, it may also cause a short circuit in the four-in-one gas detector, or a change in the resistance value of the circuit, leading to detection failures.
Formaldehyde is a colorless and easily soluble irritating gas. Man-made boards such as particleboard, medium-density fiberboard, and plywood, adhesives, and wallpaper are the main sources of formaldehyde in the air, with a release period of up to 3 to 15 years. It can be absorbed through the respiratory tract. The harm of formaldehyde to the human body is characterized by long-term, latent, and hidden features. Long-term inhalation of formaldehyde can trigger serious diseases such as nasopharyngeal cancer and laryngeal cancer.
For example, after formaldehyde comes into contact with paper, the reagent contained in the paper will react with formaldehyde to form a compound, and the color will change from white to yellow. The degree of color change can reflect the amount of reflected light from the received light. The intensity change rate of the reflected light amount can be used as a response to the gas concentration. By presetting the calibration curve, the concentration of the gas can be determined by detecting the response value of the target gas.
