Four-in-one gas detector fault detection

The four-in-one gas detector is a single gas or multiple gas detector that can be configured flexibly. It can be equipped with an oxygen sensor, a combustible gas sensor, and a toxic gas sensor or optionally four gas sensors or optionally a single gas. sensor. Four-in-one gas detector has a very clear large LCD screen, backlight illumination, sound and light vibration alarm, to ensure that dangerous gases can also be detected in a very unfavorable work environment and prompt prompt operation personnel to prevent.

The principle of the detection part of the four-in-one gas detector is that when the concentration of the flammable gas to be measured exceeds a limit value, the output voltage of the amplified bridge circuit and the set detection voltage of the circuit are detected. Through the voltage comparator, a square wave generator outputs a set of squares. Wave signal, control sound, light detection circuit, buzzer continuous sound, light-emitting diodes flash, send out the detection signal. From the principle of a four-in-one gas detector, one can see that if electromagnetic interference affects the signal detected, data deviation occurs; if a collision or vibration occurs, the device will be disconnected and the detection will fail; if the environment is too humid or the equipment enters water, it is also possible. A short circuit may occur in the four-in-one gas detector, or the line resistance value may change, and a detection failure may occur.

Formaldehyde is a colorless, soluble, irritating gas. Particleboards, density boards, plywood, and other man-made boards, adhesives, and wallpapers are the main sources of formaldehyde in the air. The release period is as long as 3 to 15 years. Can be absorbed through the respiratory tract, formaldehyde harm to the human body with long-term, latent, hidden features. Long-term inhalation of formaldehyde can cause serious diseases such as nasopharyngeal cancer and laryngeal cancer.

For example, the formaldehyde contained in the paper will react with formaldehyde to form compounds, and the color will change from white to yellow. The degree of discoloration reflects the amount of light reflected by the light received. The intensity change rate of the amount of reflected light can be used as a gas concentration response. By setting the calibration curve in advance, the gas concentration can be determined by the response value of the target gas.

The four-in-one gas detector consists of two parts: detection and detection, with detection and detection capabilities. The principle of the detection part of a four-in-one gas detector is that the sensor of the instrument uses a detection element, a fixed resistance, and a zero adjustment potentiometer to form a detection bridge. The bridge uses a platinum wire as the carrier to catalyze the element. After the power is applied, the temperature of the platinum wire rises to the working temperature, and the air reaches the surface of the element by natural diffusion or other means. When there is no flammable gas in the air, the bridge output is zero. When the flammable gas is contained in the air and diffused on the detection element, flameless combustion occurs due to catalysis, so that the temperature of the detection element is increased and the resistance of the platinum wire is increased. The bridge circuit is out of balance and there is a voltage signal output. This voltage is proportional to the concentration of flammable gas. The signal is amplified and converted by analog to digital. The liquid display shows the concentration of flammable gas.