What kind of gas sensor is generally used in formaldehyde detector?

It seems that Xuzhou Jincheng Instrument uses a JCTSL 230 sensor.

Summary. For example, methane, hydrogen, ammonia, ethane, toluene, formaldehyde, etc., can be detected with combustible gas alarms, because the gases you are talking about are all combustible gases. As long as it is a gas that can spontaneously ignite, it can be detected with a combustible gas alarm.

Combustible gas alarm manufacturers are better domestic ones such as Neurophth, Corteus, Ampal, etc.; Imported ones include Dräger, Honeywell, Mesian Akut, and so on.

For example, methane, hydrogen, ammonia, ethane, toluene, formaldehyde, etc., can be detected with combustible gas alarms, because the gases you are talking about are combustible gases. As long as it is a gas that can spontaneously combust, it can be detected by a combustible simple slag gas alarm. Combustible gas alarm manufacturers are better domestic ones such as Neurophth, Corteus, Ampal, etc.; Imported ones include Dräger, Honeywell, Mesian Akut, and so on.

What kind of gas is used for poison testing?

The instrument uses a 4-electrode electrochemical sensor consisting of a working electrode and an active auxiliary electrode. The signal emitted by the auxiliary electrodes is used for temperature compensation, which enhances the selectivity of the entire sensor. The sensor response is proportional to the formaldehyde concentration in the air.

Different types of formaldehyde detectors use different gas sensors, and the working principles are naturally different, as follows:

1. Semiconductor sensors.

It is manufactured using some metal oxide semiconductor materials, and at a certain temperature, the conductivity changes with the change of the composition of the ambient gas. For example, the alcohol sensor is prepared using the principle that when tin dioxide encounters alcohol gas at high temperatures, the resistance will decrease sharply.

2. Combustion sensor.

This sensor is to prepare a high-temperature resistant catalyst layer on the surface of the platinum resistor, at a certain temperature, the flammable gas catalyzes combustion on its surface, and the combustion is a function of the temperature increase of the platinum resistor, the change of resistance, and the change value is a function of the concentration of the flammable gas.

3. Electrochemical sensors.

A considerable part of its flammable, toxic and harmful gases have electrochemical activity and can be electrochemically oxidized or reduced. Using these reactions, it is possible to distinguish the gas composition and detect the gas concentration.

Nowadays, most of the formaldehyde detection instruments on the market use the principle of high-sensitivity electrochemical sensors, combined with single-chip microcomputer technology and network communication technology to collect air samples from the detection site, and the formaldehyde in the air is absorbed by the phenol reagent solution, and the reaction generates azine, which is oxidized by the chromogenic agent iron iron ions in the acidic solution to form blue-green compounds. According to the color shade, it is directly colorimetric determined on site. You can know the residual formaldehyde concentration in the air.

The formaldehyde sensor is used by people to detect formaldehyde gas, and it is specially used for gas detection. Formaldehyde sensors include formaldehyde oxide gas sensors, formaldehyde gas molecular sieve sensors, formaldehyde surface acoustic wave gas sensors, visual fluorescent formaldehyde sensors and formaldehyde gas electronic noses. At present, there are not many formaldehyde sensors, including formaldehyde gas reduction oxide gas sensor based on formaldehyde gas, visual fluorescent formaldehyde sensor based on silica gel particles, formaldehyde acoustic surface wave gas sensor, formaldehyde gas molecular sieve sensor based on molecular sieve adsorption mechanism and formaldehyde gas electronic nose.

Formaldehyde oxide gas sensor has been studied a lot, and the sensitivity and recovery-response characteristics have also reached a certain height, but the selectivity is not high, mainly due to the interference of methanol, ethanol, benzene, toluene, hydrogen sulfide, ammonia, alcohol, liquefied gas, gasoline, etc., but the interference gas of different gas sensing elements is different, and the method of composite doping can be used to improve its selectivity. In addition, the selectivity of formaldehyde gas oxide sensor can be improved by properly using the resistance-temperature characteristics of the sensor, and the sensitivity and response-recovery characteristics of the gas sensor can be further improved by reducing the material particles, increasing the specific surface area and improving the preparation process of the gas sensitive material.

The visual fluorescence formaldehyde sensor has good selectivity and linear response, and it can be visualized without the help of any spectroscopic instrument, but its recovery-response characteristics and sensitivity need to be further improved. It can be used for qualitative and semi-quantitative visualization of formaldehyde detection.

SAW formaldehyde gas sensor is affected by temperature and humidity, and the selectivity and sensitivity are not high to compensate for temperature and humidity. Finding sensitive films with better formaldehyde selectivity, stronger adsorption and higher sensitivity and improving the quality of film coating are the two directions to improve their gas sensing performance.

The selectivity and sensitivity of formaldehyde gas molecular sieve sensors need to be further studied, and the recovery-response characteristics need to be further improved. If new adsorbents can be found with a stronger formaldehyde adsorption capacity, the performance of the sensor can be improved.

Use Xiangchong's formaldehyde detector to measure formaldehyde, real-time display on the large screen, triple alarm preset function, portable and small handheld, what is the formaldehyde content, whether it exceeds the standard, how much it exceeds the standard, these are all data on the instrument can be seen. Then according to the test results of the instrument, the use of treatment, you can buy some formaldehyde removal products online, usually pay more attention to ventilation indoors, or buy some spider plants, tiger tail orchids and other green plants can reduce formaldehyde concentration. Formaldehyde gas electronic nose has strong anti-interference ability, specific response, high sensitivity, accurate measurement results, low detection limit, and good recovery-response characteristics, which is a comprehensive application of a variety of sensors and computer technologies.

Formaldehyde gas electronic nose is a composite of a variety of formaldehyde sensors, with good comprehensive performance, which is the key direction of formaldehyde gas sensor research in the future.

Formaldehyde mainly exists in gaseous form, so the detection of formaldehyde is mainly to detect formaldehyde gas. The selectivity of the existing formaldehyde sensors is not high, so improving the selectivity of formaldehyde sensors will be a progress direction in future research, and the selectivity of multiple compounds and the appropriate use of the resistance-temperature characteristics of the sensors can be improved. Due to the great harm of formaldehyde, it is also very important to improve its sensitivity, lower detection limit and recovery-response characteristics. In addition, reducing the size and miniaturization of formaldehyde sensors is also a focus of future research. To improve the comprehensive performance of formaldehyde gas sensors, on the one hand, it is necessary to find better gas-sensitive materials and improve the manufacturing process; On the other hand, it is necessary to carry out multi-faceted synthesis and composite various sensors, but this will increase its volume and cost, so reducing the volume and cost has become the focus of its research.

The vertical structure of a community refers to the configuration of the community in the vertical aspect, and its most significant feature is the phenomenon of stratification, that is, the phenomenon of dividing into many layers in the vertical direction.

The stratification of the community includes above-ground strata and subsurface stratigraphy. The differentiation of layers is mainly determined by the life form of plants, and the height of the plants in the air and the depth they reach in the soil are different, while the aquatic community forms a hierarchical arrangement of species at different depths below the water surface, so that there is a phenomenon of chain and layer socks arranged by the height (or depth) of plants in the community.

The stratification phenomenon was the most obvious in the forest community, and the stratification of temperate broad-leaved forest and coniferous forest was the most typical, and the stratification structure of tropical forest was the most complex.

1. Multi-function: it can detect formaldehyde, benzene, ammonia, toluene, xylene, and TVOC harmful gases in indoor air at the same time.

2. Time, temperature and humidity display: In order to meet the needs of indoor environment monitoring, the instrument can display the date and time of sampling, temperature and humidity on site, and can be printed out together with the test results.

3. Automatic control: the time can be set arbitrarily within 0 99 minutes, the operation is convenient and intuitive, and the work will automatically stop at the end of sampling;

4. Shunt control: this instrument adopts 6 motors, 6 pumps, large flow and independent gas circuit structure, in the sampling process, each sampling flow does not interfere with each other, and 6 channels can be selected to work at the same time or any gas path can be selected according to actual needs;

5. Data adjustment: The machine can be adjusted according to the needs of the test to produce different test results, and the data of the machine can be calibrated by itself.

6. Independent and lightweight: this instrument is small in size, light in weight, easy to carry, built-in sampler, no need to purchase another gas sampler;

7. Beautiful: color PC** panel, touch buttons, beautiful and exquisite;