Hanwei MQ135

This component has been deleted. It can no longer be used in designs.

Reference Designs (8)

Attributes

Part Number
Manufacturer
Description
Datasheet
Prefix
U
Lead Free
???
Octopart Part Number
Package
RoHS
???

Pins

1
5v
2
5v
3
GND
4
OUT
5
--open
6
open

Contributors

Datasheet Preview

HANWEI ELCETRONICS CO.,LTD MQ-135 http://www.hwsensor.com
TEL: 86-371-67169070 67169080 FAX: 86-371-67169090 E-mail: sales@hwsensor.com
TECHNICAL DATA
MQ-135 GAS SENSOR
FEATURES
Wide detecting scope Fast response and High sensitivity
Stable and long life Simple drive circuit
APPLICATION
They are used in air quality control equipments for buildings/offices, are suitable for detecting
of NH3,NOx, alcohol, Benzene, smoke,CO
2
,etc.
SPECIFICATIONS
A. Standard work condition
Symbol Parameter name Technical condition Remarks
Vc Circuit voltage 5V±0.1 AC OR DC
V
H
Heating voltage 5V±0.1 ACOR DC
R
L
Load resistance can adjust
R
H
Heater resistance
33Ω±5%
Room Tem
P
H
Heating consumption less than 800mw
B. Environment condition
Symbol Parameter name Technical condition Remarks
Tao Using Tem
-10-45
Tas Storage Tem
-20-70
R
H
Related humidity less than 95%Rh
O
2
Oxygen concentration 21%(standard condition)Oxygen
concentration can affect sensitivity
minimum value is
over 2%
C. Sensitivity characteristic
Symbol Parameter name Technical parameter Ramark 2
Rs Sensing
Resistance
30KΩ-200KΩ
(100ppm NH
3
)
α
(200/50)
NH
3
Concentration
Slope rate
0.65
Standard
Detecting
Condition
Temp: 20℃±2 Vc:5V±0.1
Humidity: 65%±5% Vh: 5V±0.1
Preheat time Over 24 hour
Detecting concentration
scope
10ppm-300ppm NH
3
10ppm-1000ppm
Benzene
10ppm-300ppm
Alcohol
D. Structure and configuration, basic measuring circuit
Structure and configuration of MQ-135 gas sensor is shown as Fig. 1 (Configuration A or B), sensor composed
by micro AL2O3 ceramic tube, Tin Dioxide (SnO2) sensitive layer, measuring electrode and heater are fixed into a
crust made by plastic and stainless steel net. The heater provides necessary work conditions for work of
Parts Materials
1
Gas sensing
layer
SnO
2
2
Electrode Au
3
Electrode line Pt
4
Heater coil Ni-Cr alloy
5
Tubular ceramic
Al
2
O
3
6
Anti-explosion
network
Stainless steel gauze
(SUS316 100-mesh)
7
Clamp ring Copper plating Ni
8
Resin base Bakelite
9
Tube Pin Copper plating Ni
A
A
Fig. 1
Configuration A
Configuration B
Fig.2
HANWEI ELCETRONICS CO.,LTD MQ-135 http://www.hwsensor.com
TEL: 86-371-67169070 67169080 FAX: 86-371-67169090 E-mail: sales@hwsensor.com
sensitive components. The enveloped MQ-135 have 6 pin ,4 of them are used to fetch signals, and other 2 are used
for providing heating current.
Electric parameter measurement circuit is shown as Fig.2
E. Sensitivity characteristic curve
Fig.2 sensitivity characteristics of the MQ-135
SENSITVITY ADJUSTMENT
Resistance value of MQ-135 is difference to various kinds and various concentration gases. So,When using
this components, sensitivity adjustment is very necessary. we recommend that you calibrate the detector for
100ppm NH
3
or 50ppm Alcohol concentration in air and use value of Load resistancethat( R
L
) about 20 KΩ(10KΩ
to 47 KΩ).
When accurately measuring, the proper alarm point for the gas detector should be determined after
considering the temperature and humidity influence.
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
-20 -10 0 10 20 30 40 50 60
degree
Rs/Ro
33%RH
85%RH
sensitivity characteristics of
the MQ-135 for several gases.
in their: Temp: 20℃、
Humidity: 65%
O
2
concentration 21%
RL=20kΩ
Ro: sensor resistance at 100ppm of
NH
3
in the clean air.
Rs:sensor resistance at various
concentrations of gases.
Fig.4 is
shows the typical dependence of
the MQ-135 on temperature and humidity.
Ro: sensor resistance at 100ppm of NH
3
in air
at 33%RH and 20 degree.
Rs: sensor resistance at 100ppm of NH
3
at different temperatures and humidities.
Fig.4
MQ-135
0.1
1
10
10 100 1000
ppm
Rs/Ro
AIR
CO2
CO
酒精
NH4
甲苯
丙酮