ZE08-CH2O Formaldehyde Gas Sensor [Arduino Sensors for Everyone]

This chapter explains how to use the ZE08-CH2O sensor. You will learn its features, operating principles, specifications, connection pin arrangement, output values, and connect Arduino and the sensor together to measure the air around you easily using the library.

 

Contents

 

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ZE08-CH2O Formaldehyde Gas Sensor 

 

Formaldehyde is also knows as oxomethane, oxymethylene, methylene oxide, methyl aldehyde, formalin, formulation, formic aldehyde, methaldehyde, methanol, etc.

 

 

 

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Effects on the human body

Formaldehyde is a very toxic substance to the human body. When the body is exposed to formaldehyde, symptoms begin to appear. In particular, formaldehyde is present in many interior materials of buildings, and is also the main culprit of new house syndrome and new building syndrome. Health effects such as irritation to the eyes, nose and throat, allergic reactions, shortness of breath, asthma, headache, etc. Respiratory system abnormalities, skin diseases and allergic symptoms may worse

 

 

Why does formaldehyde get worse as it gets hotter?

 

The results of a research by a research team at Washington State University in the US found that the higher the indoor temperature, the higher the concentration of formaldehyde in the indoor air. By looking at the correlation between indoor and outdoor air temperatures, indoor temperatures, and when the formaldehyde concentraition is at the highest level, results showed that in summer, formaldehyde increased steadily as the indoor air temperature increased. Many studies saw that an increase in indoor temperature affects the increase in the concentration of formaldehyde.

 

When we watch the news, we hear of large heatwaves coming every year. People also complain hot summer days and the unbearable heat is brings.”The summer rainy season is over, and the heat is coming.”

 

Hot weather does not only imply the outdoor temperature. When you enter the house, it can also be hot. The heat from the building can make you feel claustrophobic. At night, it is often hotter inside than outside. Are buildings and walls, various interior materials, and furniture simply radiating heat? As the temperature rises due to the hot weather, and buildings become hot, formaldehydes from the building, walls, furniture, and interior materials are spewed out. In addition, during winter, high indoor temperatures are maintained due to heating. The problem of increasing indoor formaldehyde concentration due to increasing indoor temperatures may become a a more serious problem in the future.

 

Therefore, if indoor ventilation is not done to avoid fine dust, it may adversely affect the human body due to an increase in formaldehyde. In other words, if indoor air is not properly managed, there is a high possibility of cancer or respiratory disease due to air pollutants such as formaldehyde.

 

At a concentration of 1ppm or less, irritation to the eyes, nose and throat is observed. Formaldehyde is especially fatal for children and the elderly with weakened immunity. It causes many diseases, such as sick house syndrome, dermatitis, and atopy. In severe cases, blindness or death can occur. A concentration of less than 0.1 ppm is dangerous for sensitive people. In particular, intense pain in the mouth, neck, and abdomen, vomiting, diarrhea, dizziness, convulsions, and unconsciousness may occur.

 

Body parts	Effects on the human body
Eye	Inflammation, dryness, itchiness
Lungs	Fatal if inhaled. Alveolar damage and inflammatory reactions, severe asthma attacks in people with bronchial asthma, cough, pressure and inflammation of the lungs.
Nose	When inhaled, it passes through the alveoli and enters the blood. It irritates the nose, throat, and eyes, causing symptoms such as allergies or colds.
Brain	Headache, increased fatigue, ADHD (carelessness, hyperactivity, impulsivity, learning disabilities, etc.)
Sskin	Skin rash, toxic if contact with skin
Nervous system	Adverse reactions to the central nervous system, immune system, autonomic nervous system, and endocrine system

 

According to a report by Schenker et al. in 1981, a survey of residents living in houses with insulation (UFFI) revealed that long exposure to formaldehyde causes emotional instability, memory loss, and difficulty concentrating. Animal experiments showed symptoms of rhinitis such as lung edema, runny nose, sneezing, itching, and stuffy nose, which made it difficult to breathe due to water in the lungs. Repeated exposure to formaldehyde causes chronic irritation to the eyes, nose and respiratory tract and is known to cause eyelid irritation.

 

Formaldehyde, which causes sick house syndrome, has been found to decrease students' cognitive function. Indoor air pollutants, such as formaldehyde, can reduce and harm some or all of their intellectual, learning, cognitive and mental health.

 

According to a study by the US Environmental Protection Agency (EPA) “Indoor Air Quality and Student Academic Performance,” poor indoor air quality degrades students' academic performance. In other words, indoor air pollutants can directly reduce concentration, computing ability, memory, etc. for students.

 

In addition, according to the experimental results of Doris J. Rapp, MD, it is concluded that the indoor environment and indoor air quality can affect children's learning ability and cognitive ability. The study rooms for children should be in a clean area. After moving, bringing in new furniture, or renovating the interior of your hourse, you should observe your child's condition. If they show any of the following symptoms, you should question the indoor air quality of that space.

 

 -My child's academic performance is poor. Learning skills such as reading, writing, and counting decline, and language skills are also poor.
-Distraction, hyperactivity, impulsivity and learning disabilities, objects are easily lost, memory is poor, and objects are often lost.
-Eyes are dry and itchy. Tears come out, and you become thirsts. You begin have a headache and your chest is stuffy

 

With these symptoms, there is also the possibility of developing a child's physical illness (e.g. atopy or chemical hypersensitivity). Dr. Doris Raf believes that indoor air quality (e.g. formaldehyde) is the leading cause of ADHD (attention deficit hyperactivity disorder: carelessness/hyperactivity/impulsivity).

 

 

 

 

[Air purifier that can filter formaldehyde]

The Dyson air purifier can destroy formaldehyde and automatically purifies the entire indoor air using a HEPA filter that removes up to 99.95% of ultrafine particles. It works on the principle that the cryptomic filter adsorbs and destroys fine dust and formaldehyde discharged from interior decoration materials, flooring materials and plants through selective catalytic oxidation on the filter surface. In addition, there are three sensors that automatically detect fine dust and gases (PM2.5, PM10, VOC, NO2) in the air, including formaldehyde.

 

 

 

 

 

 

 

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ZE08-CH2O Sensor?

The ZE08-CH2O sensor is a gas sensor that can detect formaldehyde. Formaldehyde in air is detected using electrochemical principles. It also has a built-in temperature sensor to calibrate the sensor value. There are analog output and digital UART output.

 

ZE08-CH2O V1.0.pdf

0.53MB

 

 

 

[WINSEN's product]
WINSEN manufactures various types of formaldehyde sensors. ZE08-CH20, ZE07-CH20, and ME3-CH2O sensors are provided.

 

 

 

 

[ZE08-CH2O sensor specification]
The measurement range of the ZE08-CH2O formaldehyde (HCHO) sensor is 0~5ppm. The resolution is ≤0.01ppm.

 

 

 

[ZE08-CH2O sensor operation principle]
The ZE08-CH2O formaldehyde (HCHO) sensor uses ME2-CH2O-16X15 and is measured by the electrochemical method.

 

 

[ZE08-CH2O sensor measured value relation to temperature and air pressure]
Temperature and air pressure must be calibrated for accurate values 

Charles's law states that at constant pressure, the volume of a gas is proportional to its absolute temperature, regardless of the type of gas. That is, as the temperature of the gas rises (1 degree), the volume increases by (1 / 273) from the initial volume at (0 degrees).

In the figure, if you extend each straight line so that the volume becomes 0, it meets at the point where the temperature is -273.15 ℃. Using absolute temperature (0 °K = -273.15 °C), the relationship between the volume of the gas and the temperature can be expressed more simply.

 

 

[Unit Conversion]
By applying the values that change according to the temperature and pressure of the gas to the formula, the values of ㎍/㎥ -> ppm, ppm -> ㎍/㎥ can be converted.

 

[DAC interface]
In DAC mode, values are read using the Arduino Analog port. In DAC mode, measurement accuracy is affected by the ADC's bit and reference voltage, so a high quality power supply or reference voltage and 10-bit ADC are recommended.

The relationship between voltage (V) and concentration (PPM) is linear 0.4V -> 0ppm 2.0V -> 5ppm Therefore, the function diagram is as follows.

 

 

 

 

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Purchasing the ZE08-CH2O sensor

As follows, the [ZE08-CH2O] sensor used in the book [Arduino Sensors for Everyone] can be purchased at Ali Express, Amazon.  

 

 

 

 

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Software Coding

Run the example file in Steamedu123_Sensor-master > examples.

/*
   @303 ZE08-CH2O Formaldehyde gas sensor
*/

#include <C303_Steam_Air_ZE08-CH2O_HCHO.h>    // Internal library header file

SteamZE08CH2O hcho(A1);          // pin number

void setup() {
  Serial.begin(9600);   // Start serial communication at a speed of 9600bps.
  hcho.begin();         // (1) Initialize the sensor.
}

void loop() {
  hcho.read();          // (2) Measure the value of the sensor.
  hcho.display();       // (3) Output the sensor value.
  delay(1000);          // Wait for 1 second.
}

 

 

 

 

 

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ZE08-CH2O Arduino sensor operation check

When the hardware connection and software coding are completed, you can check the operation screen as follows.

 

------------------------------------------------------ 
Development environment: WINDOWS 10
Arduino IDE: 1.8.13
------------------------------------------------------ 

 

01 library copy

You can easily check the operation by using the  library.  
The libraries \Steamedu123_Sensor-master folder is copied to the folder below.
* This folder is created automatically after installing Arduino C:\Users\s\Documents\Arduino\libraries

02 *. ino file execution
-Connect Arduino and PC
-Run Arduino IDE
-Menu → Tools → Board: Check Arduino UNO
-Menu → Sketch → Check/Compile

03 Check compilation

Select Sketch>OK/Compile (CTRL+R) to compile.

04 Arduino Uno upload

When the compilation is completed without any problems, select Sketch>Upload (CTRL+U) to upload the compiled file.

05 Operation check

You can check the operation as follows.
 

 

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Wrap-up

You can connect Arduino and [ZE08-CH2O] sensor and practice the sensor easily with simple coding.

 

In this section, we examined the effects of formaldehyde on the human body, the standard concentration, the measurement range of simple measuring instruments, and the sensors used in the measuring instruments. We also controlled the sensor using UART and DAC.

 

Indoor air filled with formaldehyde adversely affects the human body, including sick house syndrome, dermatitis, and atopy, as well as directly reducing concentration, computing ability, and memory for students. 

 

Since formaldehyde cannot be removed with an air purifier, the ZE08-CH2O sensor should be used to check formaldehyde levels, and if it is bad or very bad, open a window to ventilate the air in the room. 

 

 

 

 

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References

References for [ZE08-CH2O formaldehyde (HCHO) Arduino sensor] used in the book [Arduino Sensors for Everyone] are as follows.

[35] Schenker, M. B. and Weiss,  S. T., International Symposiumon Indoor Air Pollution, Health and Energy Conservation, Amherst, MA, 1981
[36] EAP, Indoor Air Quality Student performance(2003),
[37] Dae-seop Kim, Sun-ju Kim, Si-young Park, Manjung Jeon, Gyutae Kim, Changyoon Kim, Jonghak Jeong, Baek Sungok, Gongjun Sa, and the effect of indoor air quality on the cognitive function of elementary school students, Journal of the Korean Occupational and Environmental Medicine, 19(1), 65-72, 2007
[38] Doris J. Rapp, Is This Your Child's World?:  How You Can Fix the Schools and Homes That Are Making Your Children Sick Paperback, 1997
[39] Indoor Air Quality Management Act, [Attachment 2] Indoor Air Quality Maintenance Standards (related to Article 3) [Enforcement 2020. 4 3.] 
[40] National Institute of Environment, Survey on the indoor air quality of new apartment houses nationwide, 2004
[41] Sangbeom Park, Eco-friendly construction materials using bamboo charcoal. Wood Processing Division, Korea Forest Research Institute, 2007
[42] ZE08-CH2O Datasheet, 
[43] DART WZ-S Datasheet, 
[44] DART  2-FE5  Datasheet, 
[45] Ali Express, ZE08-CH2O, 
[46] Ali Express, DART WZ-S, 
[47] Ali Express, DART 2-FE5,
[48] ZE08-CH2O V1.0 Datasheet, “Technical Parameters”, p3
[49] ZE08-CH2O V1.0 Datasheet, “Pin Description”, p4
[50] KoaMise S4, 
[51] MG/M3 TO PPM, 
[52] Amazon, DM106C, 

 

 

 

 

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Purchasing a book

[Arduino Sensors for Everyone] The book is available for purchase on Google Book and Apple Books.

In this book, you will learn how to use the PMS7003, GP2Y1010AU0F, PPD42NS, SDS011 Fine Dust Sensor, DHT22 temperature/humidity sensor, MH-Z19B carbon dioxide sensor, ZE08-CH2O formaldehyde sensor, CCS811 total volatile organic compound (TVOC) sensor , GDK101 radiation (gamma ray) sensor, MQ-131 ozone (O3) sensor, MQ-7 carbon monoxide sensor, MICS-4514 nitrogen dioxide sensor, MICS-6814 ammonia sensor, DGS-SO2 sulfur dioxide (SO2) sensor, BME280 atmospheric pressure sensor, GUVA-S12SD ultraviolet (UV) sensor, MD0550 airflow sensor, and QS-FS01 wind speed sensor.

 

[Google play book]

Arduino Sensors for Everyone, 저자: Ronnie Kim - Google Play 도서