Product Specification Book

Modify the record table:

one, Product Introduction

MQ-7S Sensitive body of the sensor uses tin dioxide with low conductivity in conventional clean air ( SnO2） It is a matrix, mixed with several rare earth elements and precious metals to sinter.This sensor uses high temperature (5 V加热）and 低温（1.5V加热）cycle Translated content, click to replace contentCO When gas is used, the sensor's resistance changes and CO The gas concentration increases and decreases.Based on this conductive characteristic, a corresponding test circuit can be designed to convert the change in gas concentration into the corresponding signal output, thereby realizing the detection of gas.

  MQ-7S The sensor is at low temperature CO The gas is very sensitive, has good reaction repeatability, and has certain anti-interference ability （Such as anti-alcohol, perfume and other impurities gases )，Long life, belongs to an excellent performance CO Semiconductor sensor.

two, Application scenarios

1、 Carbon monoxide combustible gas alarms for household and industrial use;

2、 Various alkanes and carbon monoxide multigas monitoring and alarms;

3、 Fireplace, kitchen utensils, gas water heaters, range hoods, air purifiers and other household appliances.

three, Features

1、 Strong anti-interference ability;

2、 Fast reaction speed and high sensitivity;

3、 Long lifespan and good stability;

4、 Simple application circuit.

Four, Technical parameters

five, Product case size diagram

Structural dimensions

Test circuit

E2exist 5Vand 1.5Circulate between.

six, Data calculation

Sensor power consumption calculation method: Ps= VC* VC* RS／(RS+ RL)* (RS+ RL)

seven, Things to note

1、Fatal damage to the sensor must be avoided

（1） Exposed to silicone gas:

Translated content, click to replace content

（2） Highly corrosive environment:

High concentration of corrosive gases, such as H2S,SQ2，CL2,HCl wait.It will corrode the sensor's sensitive body material or heating wire.

（3） Alkaline metal pollution:

The performance of the sensor will decline after being contaminated by alkali metals, such as the impact of salt water spray is very obvious.This decline can also occur when exposed to some inorganic elements.

（4） Contact with liquid water or icing on the sensor:

The sensor's sensitive material has water splashed in or was soaked, which will cause a decrease in sensitivity characteristics.If water freezes on the sensitive body, it will cause the sensitive body to break, thereby changing the characteristics of the sensor.

（5） The sensor operating voltage or heating voltage is too high:

The voltages that are subjected to both ends of the sensor heating wire must be applied according to the specified value, if they are higher than the specified value.It may cause the heating wire to become brittle or break.If the voltage is too high at both ends of the sensitive electrode, the characteristics of the sensor will also decrease.

（6） Wiring error:

for MQ-7S Product, if the voltage is added to the A,Aor B,Bor A,Hor B,H On the pin, the leads will break.Added A,B The sensor on the foot is not working.As shown:

2、When using the sensor, try to avoid the following situations

（1） Condensate

When used indoors, a small amount of condensate generally does not affect the use of the sensor.However, if condensate remains on the surface of the component for a long time, the sensor's sensitive characteristics will decrease.

（2） Working in high concentrations of measured gas

Regardless of whether the sensor is in power-on state, it is in high concentrations of gas (usually tens of thousands). ppm Above) Medium length

Time placement will affect the sensor characteristics.

（3） Long-term storage

If the sensor is not powered on for a long time, it will cause its own resistance to drift reversibly, which changes with the surrounding environment.Therefore, the sensor should be stored in a sealed environment with clean air and should not use silicone.After the sensor is stored for a long time, it must be powered on and preheated for a long time to restore it to a stable state.

（4） The environment around the sensor is poor for a long time

Regardless of whether the sensor is in power-on state, the sensor cannot be in high humidity, high temperature, or high pollution environment for a long time.These extreme conditions can reduce the sensor sensitivity characteristics.

（5） Vibration or impact

Strong vibration or impact may cause internal leads to breakage, so you should pay attention to this situation when transporting or producing and assembling.

（6） Tin welding

Such sensors are recommended to be soldered manually.Try to avoid using reflow soldering if not sufficiently tested and reasonable technical guidance.

eight, quality assurance

Product factory Translated content, click to replace content