This example shows how to work with a gas sensor (MQ-2) with Facilino

1. Programming
Gas Sensors with Facilino
Leopoldo Armesto
Senior Lecturer
Universitat Politècnica de València
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2. Outline
Material
Worked Instructions
Sensor Calibration
Heat-up the Gas Sensor
Exercises
Calibrating a Gas Sensor.
Alcohol Meter.
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3. Material
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Wemos D1 R32 with Arduino Multisensor Shield, MQ-2 Gas Sensor

4. Worked Instructions
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Main instructions

5. Sensor Calibration
Sensor response (datasheet):
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Rs/R0 value at clean air is 9.83 (aprox.)
R0=(4095-value)/(value*9.83)
Sensor resistance:
10log10 200+
log10
4095−𝑣𝑎𝑙𝑢𝑒
𝑅0∗𝑣𝑎𝑙𝑢𝑒∗9,83
−𝑎
𝑏
slope
Gas concentration (ppm):
intercept

6. Heat-Up the Gas Sensor
Approximately takes 30 minutes to heat-up.
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MQ-2 after calibration provides
1.76kOhms

7. Calibrating a Gas Sensor
Calibrate MQ2 sensor and obtain the value of R0.
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8. Alcohol Meter
Measure the alcohol (in air) in p.p.m.
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9. Programming
Gas Sensors with Facilino
Leopoldo Armesto
Senior Lecturer
Universitat Politècnica de València
9