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Topic: Finding the approximation equation for MAX30105 (Read 292 times) previous topic - next topic

chandantaluja

I am working on MAX30105 sensor, and i have got the curve of sensor voltage v/s smoke ppm as output of this sensor.

Kindly help me to plot appropriate equation for this curve.

I have attached the curve.


el_supremo

That doesn't look like it's a valid curve. A smoke density of 3ppm can be indicated by six different voltages.
Where did you get that curve from?

Pete
Don't send me technical questions via Private Message.

jremington

#2
Nov 12, 2018, 05:03 pm Last Edit: Nov 12, 2018, 05:04 pm by jremington
Those data are so noisy that it will be impossible to fit any useful curve.

How did you determine the "smoke value in PPM" for each data point?

For a tutorial on device calibration, see https://learn.adafruit.com/calibrating-sensors/why-calibrate

chandantaluja

That doesn't look like it's a valid curve. A smoke density of 3ppm can be indicated by six different voltages.
Where did you get that curve from?

Pete
I ran max30105 and MQ-2 simultaneously. the three outputs of max30105 and the smoke output of MQ-2 was observed. After this I averaged the values I received appropiately to derive this.

Each output from the LED of the MAX30105 was converted into a voltage and the values were plotted then.


jremington

Why do you think the MQ-2 data mean anything?

chandantaluja

because i needed something for reference and i couldn't find any other smoke sensor

jremington

#6
Nov 15, 2018, 03:23 pm Last Edit: Nov 15, 2018, 03:27 pm by jremington
It is not that simple.

First, the MQ-2 is not a smoke sensor, it is a gas sensor that works mainly for detecting H2, LPG, CH4, CO and alcohol. It needs to be "burned in" and calibrated properly to measure anything.

The MAX30105 is also not a smoke sensor. It measures backscattering of light from particles in the air, and the quantity measured does not have a simple relationship to whatever you think the "PPM of smoke" might be.

chandantaluja

It is not that simple.

First, the MQ-2 is not a smoke sensor, it is a gas sensor that works mainly for detecting H2, LPG, CH4, CO and alcohol. It needs to be "burned in" and calibrated properly to measure anything.

The MAX30105 is also not a smoke sensor. It measures backscattering of light from particles in the air, and the quantity measured does not have a simple relationship to whatever you think the "PPM of smoke" might be.
okay. Got your point.

Any suggestions to what I can use for smoke detection? any sensor or something?

jremington

You could tap into a smoke alarm, or use the active element from one. But most contain a nasty chamber with radioactive material inside.

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