MQ135 View Datasheet(PDF) - Futurlec

Part Name

Description

View to exact match

MQ135

GAS SENSOR

Futurlec 

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

10

MQ-135

Fig.3 is shows the typical

sensitivity characteristics of

the MQ-135 for several gases.

in their: Temp: 20

AI R

Humidity: 65%

CO2

O2 concentration 21%

CO

RL=20kΩ

¾ ¾Æ«

Ro: sensor resistance at 100ppm of

NH4

¼ ±× ½

± Íû ª

NH3 in the clean air.

Rs:sensor resistance at various

concentrations of gases.

1

0. 1

10

ppm

100

1000

1. 8

1. 6

1. 4

33%RH

Fig.4 is shows the typical dependence of

the MQ-135 on temperature and humidity.

1. 2

85%RH Ro: sensor resistance at 100ppm of NH3 in air

1

at 33%RH and 20 degree.

0. 8

Rs: sensor resistance at 100ppm of NH3

0. 6

at different temperatures and humidities.

0. 4

Fig.4

0. 2

degr ee

0

- 20 - 10

0

10

20

30

40

50

60

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 NH3 or 50ppm Alcohol concentration in air and use value of Load resistancethat( RL) 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.

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