You should choose according to five conditions.
1. Replace electrochemical sensor with semiconductor sensor.
The sensor is the core and heart of the detector, and it is also the most expensive component. Bad merchants replaced the imported electrochemical formaldehyde sensor with a semiconductor air sensor whose market price was less than 10 yuan. Due to the limitation of domestic technology, the electrochemical formaldehyde sensors that can meet the accuracy requirements in China are almost blank, all of which depend on imports, and the cost is high. Semiconductor sensor has low cost and simple manufacture, but it can only make qualitative judgment because of its unstable heating, which can not meet the digital display requirements of the instrument and is generally not used in the instrument.
2, use a sensor to output multiple sets of data, and lie that they are all in one.
The multifunctional formaldehyde and TVOC detector of regular manufacturers can only output one signal from one sensor and get one index. If there are several indicators, there must be several different sensors, which will increase the cost accordingly. Bad businesses use an air sensor with a few dollars to simulate multiple sets of data through software, claiming that the comprehensive formaldehyde and TVOC air detector is purely deceptive.
3. Misunderstanding of the accuracy of 0.00 1
According to the national standard GB\T 18883-2002 "Indoor Air Quality Standard", the formaldehyde concentration is accurate to two decimal places, so is the professional instrument with tens of thousands of yuan. Bad businesses rely on data to simulate fake three digits, which is purely a bluff. Everyone should keep their eyes open when shopping. If the formaldehyde detector you buy can be accurate to three decimal places, there is no doubt that this business is unreliable!
So how to distinguish fake formaldehyde detector teaches you the following tricks.
Look at the sensor first. Household formaldehyde detector usually adopts electrochemical sensor method, which has been proved by authoritative organizations at home and abroad.
First, "hope". By observing the sensor type through the air inlet of the detector, the electrochemical sensor has a large volume and a white diaphragm, while the semiconductor sensor has a small volume and the color is generally gray or black.
Second, "smell and ask." You can consult the sensor type of the merchant. If it is a semiconductor, it can't be measured if it is directly passed.
Cut again. Looking at the price, the market price of a single imported electrochemical formaldehyde sensor is 200-300 yuan, and the manufacturer needs 100 yuan for bulk purchase. In addition, the wages of circuit boards, display screens, rechargeable batteries, housings, packaging and production workers total 100 yuan, and the direct cost of manufacturers is more than 200 yuan. Coupled with national taxes, operating expenses and reasonable profits, the lowest terminal price is also above 300 yuan. Therefore, it is almost impossible for regular manufacturers below 300 yuan to buy electrochemical formaldehyde detectors.
Second, look at accuracy.
As mentioned above, the national standard GB\T 18883-2002 Indoor Air Quality Standard, the formaldehyde concentration is accurate to two digits after the decimal point, that is, accurate to 0.0 1mg/m3, and the products of regular manufacturers are designed in strict accordance with national standards. If a merchant's advertising accuracy is 0.00 1, it can basically be determined as a cottage product of an informal manufacturer.
Third, look at calibration.
Regular manufacturers have complete R&D and production equipment, and the testing instruments must be calibrated in the calibration warehouse before leaving the factory to ensure the accuracy of the products. The electrochemical detector only needs to be calibrated once without frequent calibration. The calibration module is an experimental module in a specific environment. The calibration of the instrument is completed in the calibration cabin, and the construction of the calibration cabin will cost hundreds of thousands or even millions. Generally, cottage enterprises will not spend this fee. If a formaldehyde detector requires users to calibrate outdoors every time they use it, it is not rigorous to assume that the formaldehyde in the outdoor environment is 0, which is also the common practice of cottage manufacturers.
Fourth, look at the standby time.
Standby time is the simplest and most effective method to judge whether the formaldehyde detector is an electrochemical sensor or a semiconductor sensor. The working power of electrochemical sensor is very small, and the main power consumption of the instrument comes from the circuit board. Semiconductor sensor works by heating, and its power consumption is more than 10 times that of electrochemical sensor. Usually, the standby time of formaldehyde detector of an electrochemical sensor is more than 5 days, and the standby time of formaldehyde detector of a semiconductor sensor will not exceed 12 hours.
Fifth, look at the manufacturer's qualification and product qualification.
First of all, look at whether the manufacturer has a formal website, and search for the name of the manufacturer, such as "Gu Bei Technology", a professional instrument manufacturer. Regular manufacturers can find websites. Understand the relevant information of the enterprise, the enterprise team, production qualification, whether the ISO product quality system has been established, and whether there are pictures of office space, workshop and factory building. Secondly, log on to the website of the industrial and commercial bureau where the manufacturer is located to further understand the authenticity, main business, establishment time, formal R&D and production qualification of the enterprise. In the case of OEM, cottage manufacturers. Log on to the website of the Trademark Office again to see if it is a registered trademark. Finally, it would be better if the product has a national patent, which means that the accuracy of the instrument is more guaranteed. You can log on to China National Intellectual Property Administration's website for enquiry.
Therefore, it is particularly important to choose a formal formaldehyde detector for testing! Answer. Paul. . . Royal can do what you want, and its test results have been certified by the state and won the support and trust of users. I hope I can help you!