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HANWEI |
HANWEI ELETRONICS CO.,LTD
MQ-307A
http://www.hwsensor.com
MQ307A CO GAS SENSOR
The MQ307A is a tin dioxide semiconductor gas sensor
which has an excellent performance in CO detection. Using a
mini-bead type sensing element with a periodic temperature
change operation method, high sensitivity, selectively,
small effect from humidity and other remarkable
characteristics have been achieved. The MQ307A realizes
the development of reliable CO detection devices.
Structure
Gas sensitive semiconductor material is a mini bead type and a heater coil
and electrode wire are embedded in the element. The sensing element is
installed in the metal housing which uses double stainless steel mesh
(100mesh) in the path of gas flow.
Operating conditions
When the sensor is operated with high/low periodic operation (Fig 2), sensor
signal changes according to the temperature dependencycharacteristics. By
detecting the sensor signal at sufficient timings (at a high temperature for
methane and at a low temperature for CO), selective detection of both
methane and CO has been achieved. Fig 3 shows the standard operation
circuit and FIg 4 shows the sensitivity characteristics of the MQ307A at low
temperature.
TEL: 86-371-67169070 67169080
FAX: 86-371-67169090
E-mail: [email protected]
Free Datasheet http://www.Datasheet4U.com
HANWEI ELETRONICS CO.,LTD
MQ-307A
http://www.hwsensor.com
A.Standard Working Terms
Symbol
VH(H)
VH(L)
VC
RL
RH
TH (H)
TH (L)
Parameter
Heater Voltage(High)
Heater Voltage(Low)
Circuit Voltage
Load Resistance
Heating Resistance
Heating Time(High)
Heating Time(Low)
Technical Terms
0.90V ± 0.10V
0.2 V± 5%
≤6V
Adjustable(> 1 KΩ)
3.8 3.8 Ω ± 0.5 Ω
30sec ± 5 sec
120 sec ± 10sec
Remarks
AC or DC
DC (polarity is important)
P S < 10 mW
Room Temperature
DT (L)
I (H)
Sampling Time(Low)
Heating Current(Low)
< 1 sec
≤ 120 mA
At the ending of Low Voltage heating
VH=0.9V
I (L) Heating Voltage(Low)
PS power
40±5mW
≤10 mW
VH=0.2V
P S = (V C - V RL ) 2/ R S
PH Heating consumption
Less than 100mw
B.Environment Conditions
Symbol
Tao
Tas
Parameter
Using temperature
Storage
Technical Terms
-20 o C to 50 o C
-20 o C to 70 o C
Remarks
Recommended Application Ranges
Temperature
RH Relative Humidity ≤ 95% RH
(O2)
Oxygen
21%±1%(Standard terms)
Not less than 18%
Concentration
02 Influence sensor performance
C. Sensitivity Characteristics
Model
MQ-307A
Symbol
Rs
(30-100)
Parameter
Sensitive Resistance
Resistance Proportion
Technical terms
(20kΩto 200 kΩ )
1.05 to 2.1
Remarks
In 200 ppm CO
Rs (30 ppmCO) / Rs (100 ppmCO)
(100-300)
Resistance Proportion 0.75 to 1.2
Standard Testing Terms: Temperature : 20 o C ± 2 o C
Rs(300 ppmCO) /Rs(100ppmCO)
V C : 5.0 V 1%
Humidity: 65%± 5%
V H : 0.9 V ± 1%
Preheating Time:more than 48 hours
R L : 50K Ω ±5%
TEL: 86-371-67169070 67169080
FAX: 86-371-67169090
E-mail: [email protected]
FreeDatasheethttp://www.Datasheet4U.com
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