MQ-D4B Flat semiconductor sensor

Products

CH4 Gas Sensor

MQ-D4B Flat semiconductor sensor

Get Price

Datasheet

Application:

1. Combustible gas leak monitoring devices and fire/safety detection systems for households, factories, and commercial use
2. Combustible gas leak alarm and gas leak detector.

Product characteristics:

1.Has good sensitivity to methane over a wide concentration range
2.Strong anti-interference ability, low power consumption, fast response and recovery, and good stability, long lifespan, low cost

1. Description

The MQ-D4B combustible gas sensor adopts a multi-layer film manufacturing process, in which heaters and metal oxide semiconductor gas sensing layers are respectively fabricated on both sides of a micro AL2O3 ceramic substrate, and encapsulated in a metal shell. When there is a detected gas in the ambient air, the conductivity of the sensor changes. The higher the concentration of the gas, the higher the conductivity of the sensor. A simple circuit can be used to convert this change in conductivity into an output signal corresponding to the gas concentration

2. Appearance and dimension

3. Technical specifications

Product model		MQ-D4B
Product type		Flat semiconductor sensor
Standard packaging		Metal encapsulation
Detection gas		Methane, natural gas, biogas
Detect concentration		300~10000ppm(Methane, natural gas)
Standard circuit conditions	Heat voltage(DC) V_H	5.0V±0.1V AC or DC
	Circuit voltage(Dc) Vc	≤24V DC
	Load resistance R_L	adjustable

Characteristics of gas sensing components under standard testing conditions	Heating resistor R_H	85Ω±15Ω(indoor temperature)
	Heating power P_H	≤350mW
	Sensitive body resistance Rs	1KΩ～20KΩ(in 5000ppm methane)
	Sensitivity S	Rs(in air)/Rs(in 5000ppm methane)≥5
	Concentration slope α	≤0.6(R5000ppm/R1000ppm methane)
Standard testing conditions	Temperature/humidity	20℃土2℃; 55%士5%RH
	Standard Test Circuit	VC: 5V±0.1V; VH: 5V±0.1V
	Oxygen concentration	21% (not less than 18%) (Oxygen concentration will affect the initial value, sensitivity, and repeatability of the sensor. Please consult for use when using at low oxygen concentrations)
	Warm-up time	no less than 48 hours
Life		10 years

4.Test Circuit

Description: The figure above is the basic test circuit of the MQ-D4B sensor. The sensor needs to apply 2 voltages: heater voltage (VH) and test voltage (VC). VH is used to provide a specific operating temperature for the sensor, and can be powered by a DC power supply or an AC power supply. VRL is the voltage on the load resistor (RL) connected in series with the sensor. VC is the voltage provided for the test of the load resistor RL, and a DC power supply must be used.

5.Characteristic curve of the sensor

1. Typical sensitivity characteristic curve of MQ-D4B

The vertical axis in the figure is the resistance ratio of the sensor (RS/R0), and the horizontal axis is the gas concentration. RS represents the resistance value of the sensor in gases of different concentrations, and R0 represents the resistance value of the sensor in clean air. All tests in the figure were completed under standard test conditions.

2. Typical temperature and humidity characteristic curve of MQ-D4B

The vertical axis in the figure is the resistance ratio of the sensor (RS/RS0). RS represents the resistance value of the sensor under different temperatures and humidity conditions containing 5000ppm methane. RS0 represents the resistance value of the sensor under 5000ppm methane and 20℃/55%RH environmental conditions.

3. MQ-D4B linear curve

4. Response recovery curve

5.MQ-D4B long-term stability curve

Request Consultation

Message*

E-mail*

Name

Tel

Your country