Is formaldehyde detection accurate, is formaldehyde detector accurate?

The formaldehyde content test results of commercially available testing instruments are inaccurate; Using the results of formaldehyde tester debugging, it takes multiple tests to get relatively accurate results; And after professional formaldehyde testing.

The results obtained are relatively accurate.

The handheld formaldehyde detectors sold on the market are relatively different, ranging from dozens to thousands, but in fact, the detection results of this kind of formaldehyde detector are very inaccurate. During the test, you only need to change the flow rate of the air around the test instrument, and the value on the instrument table will be changed.

Formaldehyde detection reagents, such words accuracy.

It is relatively high, but it is necessary to purchase different brands and batches of reagents for testing in order to accurately detect whether formaldehyde exceeds the standard. Moreover, the reagents for testing formaldehyde are time-sensitive, and long-term placement will lead to the problem of drug failure of the reagents, and the results will be more accurate after multiple tests.

When professional testing companies test formaldehyde content, they first collect air indoors and send it to the laboratory for testing, and the results of laboratory tests will be more accurate, but it will be more expensive.

Some testing companies will use more professional formaldehyde testing instruments for testing, but the internal parameters of this instrument can be manually adjusted, so the credibility will be reduced.

Formaldehyde detectors are generally accurate。The formaldehyde detection instrument adopts the principle of high-sensitivity electrochemical sensor, 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.

Direct colorimetric determination in the field according to the color shade. Because the detection value of indoor pollution has a great relationship with the temperature, humidity, air pressure, etc. of the detection environment, according to the normal detection, the detected value will often deviate from the expectation. Formaldehyde detection refers to the quantitative detection of formaldehyde contained in air, water, food, clothing, plates, leather, etc. through specific methods or instruments.

Features of formaldehyde detector

It is not affected by extreme high temperature and humidity environment, and has a humidity compensation function. Formaldehyde readings are displayed in ppm or mg m units. One-button operation for fast sampling and fast recovery time.

The standard configuration includes a formaldehyde correction source (valid for six months) and the calibration procedure can be completed in a matter of seconds. Supplied with 10 phenol filters to exclude the influence of phenol on readings.

Optional computer remote control software and adapter make the formaldehyde detector a wireless monitoring system. Users can also choose to use a basic data processing device to print data in real time. Formaldehyde detection reagent, used together with air detection instruments, can detect the concentration value of various gases in more than 10 minutes.

Formaldehyde testing companies are still relatively accurate, because they can be measured by equipment, and the formaldehyde content in the house, so it is also very worthwhile for you to measure formaldehyde.

Precisely, you can also put some green plants at home and observe its changes, formaldehyde emission is a process that generally takes three to five years.

Let's put it this way, there are many bad companies now, and they dare to do anything in order to make money, so they are not optimistic, and the detection effect in big cities is a little better.

In addition to formaldehyde, there is another important aspect before the formal construction, that is, the formaldehyde content detected in the closed state of the indoor space, and the corresponding measures are taken according to the corresponding value of indoor harmful gases, which is a correct and targeted, and strong formaldehyde removal process. Today, professional formaldehyde removal companies will tell you whether the values detected by the so-called formaldehyde testing products are accurate.

One: Formaldehyde detection products are not allowed to sell very well.

Second: the formaldehyde detector does not meet the testing standards at all.

Three: The reason for the good sales is that it is relatively cheap.

There are dozens of dollars of household formaldehyde detectors, or even less than 10 yuan of formaldehyde self-inspection boxes, some merchants clearly say that the detection is not allowed to return, some merchants proudly say that their products quote imported testing technology, and some businesses say that the detector can detect a variety of harmful substances. The product itself and the promotional content of the business can not be communicated, only a few dozen dollars of things, the function is actually richer than the laboratory equipment, ** is so low, if such a testing instrument can play a role, you have to bother to do what professional equipment? ? , trying to launch a so-called formaldehyde detection product, so that consumers are happy to give money to the unknown, and merchants are making a lot of money.

In the age of the internet, all kinds of products are in front of us, and according to the practice that single episodes are fools, smart people will know how to tell the difference.

At present, the quality of formaldehyde detectors is uneven, and the general error is large. According to the 2017 comparative test report of household formaldehyde detector boxes released by the Shenzhen Consumer Council, all the 7 formaldehyde detection instruments involved in the detection have large errors, with the highest error of 228%.

The formaldehyde detection box uses the mechanism of specific liquid to absorb the discoloration of formaldehyde and other substances, and compares the discoloration with the human eye with the standard colorimetric card to obtain the test results. It is a semi-quantitative test, which can only determine the general situation and has low accuracy. In addition to the influence of temperature and humidity and sampling method, the judgment of detection results is also affected by light and viewing angle factors.

For example, the formaldehyde concentration on the color card of the test box is not much different from the actual one, but the former is up to standard, and the latter is twice as high as the standard.

2 3 In fact, at present, China does not stipulate that civilian portable detectors need to be certified before they are listed, so they cannot be used as measuring instruments. Therefore, the quality of civilian portable detectors on the market is uneven.

Moreover, there are still bottlenecks in gas sensor technology. The sensor of household formaldehyde detection equipment is simple in structure, small in size, and relatively low, so the accuracy should be discounted. As a result, monitors on the market that use poor-quality sensors are far from being accurate to professional equipment.

At present, there are two main types of portable detectors: semiconductor detectors and electrochemical detectors. Either way, the air velocity, humidity, and temperature will have a significant impact on the accuracy of the data.

It is rumored that many household formaldehyde detectors are just a simple patchwork of electronic components, so they cannot bear the role of indoor air quality monitoring, and there will be wrong guidance.

3 3 indoor air is invisible and intangible, so formaldehyde and other harmful gases are also known as "invisible killers", for the sake of safety, it is best to ask a professional qualified third-party testing agency to come to the door before moving in.

Some are inaccurate, and TV has been reported to the press.

According to relevant people, in fact, the formaldehyde detector (box) sold on the Internet is basically the principle of colorimetry, which uses specific liquids to absorb formaldehyde and other substances after discoloration, and compares the discoloration with the standard colorimetric card to obtain the test results. However, this is a semi-quantitative test, which is highly subjective and has low accuracy, and the ambient light, temperature and humidity, as well as the observer's operation method, observation angle, color discrimination sensitivity, etc., will affect the result reading. Therefore, the results of self-testing at home with commercially available formaldehyde test kits are less reliable and have little practical significance.

Household formaldehyde detector generally uses electrochemical method, there is an electrochemical sensor on the instrument, which is composed of two metal electrodes and electrolyte, formaldehyde gas molecules undergo redox reaction under the electrode voltage, producing a current signal proportional to the concentration of formaldehyde in the air, which shows the concentration of formaldehyde through amplification and digital processing circuit. Relevant people remind everyone that there are two kinds of portable detectors on the market at present: semiconductor detectors and electrochemical detectors.

Either way, the air velocity, humidity, temperature, etc., will have a great impact on the accuracy of the data.

Formaldehyde detection instrument, formaldehyde detection, is the data accurate?

Jincheng Environmental Protection's F3500 voice broadcast formaldehyde analyzer uses imported sensors, the touch screen feels the same as Apple's mobile phone, the detection value can be accurate to three decimal places, high-end quality, close to the people, and super cost-effective.

When testing, pay attention to the testing process.

Relatively accurate.

Formaldehyde detection has national standards that can be followed, the detection principle is actually very simple, the most commonly used in the laboratory is also particularly suitable for measuring indoor formaldehyde is the phenol reagent method, the conditional will use chromatography, the instrument is more expensive than the cost of detection.

In 2019, CCTV also reported that most of the detectors on the market are inaccurate or have a large error, and even the detection of many exceeding the standard is not exceeded, formaldehyde is still very harmful, life is only once, how important and happy health is, and how sympathetic it is to see so many water drops.

I will share what I have learned with you, I hope it will be helpful to you, and you can make a discernment.

First, the electrochemical method of direct reading of the instrument, can achieve real-time reading, but many of the low-end sensors used are easy to fail due to environmental impact (to be honest, there is still a lot of room for improvement in domestic sensors), so that the detection results and the actual deviation is large, dozens of hundreds of such instrument sensors are not formaldehyde sensors at all, known as "air anemometer", this kind of instrument does not have tens of thousands of dollars don't want to measure indoor formaldehyde, indoor formaldehyde is relatively small if it exceeds the standard, and the sensitivity requirements for this kind of detector are particularly high;

The second is the formaldehyde kit, the detection principle is based on the national standard method phenol reagent chromogenic method, and the detection is relatively reliable in the first category (except for those in tens of thousands may be better), but the national standard law stipulates that 10 liters of air need to be collected quantitatively using a sampler, and the self-test box only stipulates: stand for 30 minutes.

How much of the volume of air reacts with the absorbent in these 30 minutes? This point is unpredictable, it may be that the indoor air circulation velocity is high and absorbs more, and the Brownian motion absorbs more quickly, on the contrary, the detection is not scientific, the randomness is too high, and it is best not to use it;

The third is a new generation: convenient pump-suction air formaldehyde detector, why is it convenient, because the professional testing company also uses the pump-suction type, compared with the traditional structure is more complex and professional, ordinary consumers will not operate, and the convenient pump-suction type on the market, optimized structure, easy to operate, although the process is the same, but it is indeed a lot simpler, completely according to the national standard detection method, the configuration of the pump-type sampler, users can collect a fixed volume of 10 liters of air by themselves, and then according to the national standard method phenol reagent chromogenic method detection, It makes up for the shortcomings of the formaldehyde kit.

Decoration air BAI gas testing process: in strict accordance with DUGB T18883-2002 and GB50325-2010 standards, testing personnel DAO door-to-door collection of air samples, laboratory testing and analysis, senior engineering engineer review and signing, issue test reports; The cycle is about 3-4 working days.

1. The importance of laboratory testing for formaldehyde and other pollutants: Formaldehyde testing in new houses is related to the life and health of you and your family, and you must experience a rigorous and complex experimental process in order to get scientific test results; The instrument that can measure formaldehyde on the spot is not scientific, the instrument cannot pass the CMA measurement certification, and its cost and reagents are relatively low, so it is mostly free or low-cost testing, and formaldehyde is detected for treatment; It cannot support the protection of life and health.

2. What to do if the formaldehyde detection exceeds the standard: our center will tailor it according to your detection value and decoration situation; While doing a good job of component analysis, trace back to the source of pollution, and give you a scientific solution and recommended use time.

3. What kind of suggestions will the industry authorities give about the removal of formaldehyde: the traditional formaldehyde treatment process is mostly high-temperature fumigation, spraying aldehyde remover, spraying photocatalyst, releasing ozone, etc.; Such processes can produce secondary pollutants as well as corrosive furniture. Formaldehyde is generally used as an adhesive, mostly existing in the inside of the board, so it cannot be used; Moreover, indoor pollutants are not only formaldehyde.

You can use an air detector or you can find it.

The testing company is expensive, and you can also use the testing version.

The box is tested by itself, and it is recommended that you use this to be convenient and save money. Before using the air formaldehyde test box, the doors and windows of the room to be tested should be closed for 2 to 3 hours. To use, open the test cassette and expose the liquid in the test cassette to the environment to be tested for 40 minutes.

Then, the color of the liquid in the test box is compared with the formaldehyde display card to determine the range of formaldehyde concentrations in the air being detected. If testing furniture, it is best to place the test box inside the furniture. After the test, the waste liquid is poured into the sewer, and the solids can be disposed of with the household waste.

If formaldehyde is detected, you have to find a way to remove formaldehyde. Experts pointed out that the best way to control indoor formaldehyde pollution is to open windows frequently for ventilation and strengthen the convection of indoor and outdoor air, and the effect is also very good. There are also Maya blue and activated carbon, which are adsorbed, they can absorb formaldehyde molecules, and the effect is a little different.

There are also photocatalysts, like Mayan blue liquids, which can be sprayed on the surface of furniture.