Calibration of Gas Sensors

Block Diagram of Setup

Pure Nitrogen

CO2 1028 ppm

500 sccm

200 sccm

200 sccmFlow rate

MFC

TGS 4161 Figaro- co2

Range: 350 ppm -10000ppm

Atmospheric concentration: 350-400 ppm

Calibrated range: 350-900 ppm

Sensor details

CO2 calibration Result

PPM is inversely proportional to o/p voltage

Emf’s at 350 ppm is consistent (Column B)

Transition from synthetic air to 350 ppm is consistent.(Column E)

But, transition from base value of 350 ppm totest gas concentration is not the values that we are looking for.(Column G) the value’s should have slightly higher as per data sheet.

Comments

As per data sheet

Note: The maximum change in emf that we noticed is around 12 mv. These should have been little bit higher as per data sheet.

Δ ppm v/s Δ EMF

0 100 200 300 400 500 6000

2

4

6

8

10

12

14

Series1

X-axis Δ PPMY-axis Δ EMF

THANK YOU