Curious About Multigas Detectors? Let's Explore How They Work and Sense Gas

Dear all,

I was out of this site for a long time due to some constraints, so I could not share my views. Apologies for that. But it's good to see many new members in this forum.

I would like to know how a multigas detector works. How does the sensor sense the gas? What is there in those sensors? How is it calibrated? I mean all the basics about the working of gas detectors.

Looking forward to your replies.

Regards,
Hansa Vyas

Dear Hansa
Let me try to answer your query...
1. I would like to know how multigas detector works?
In multi gas detectors, different sensors are present in built which suited for different gases... As detectors measure a gas concentration, the sensor responds to a calibration gas, which serves as the reference point or scale... As a sensor's detection exceeds a preset alarm level, the alarm or signal will be activated...
2&3. How does the sensor senses the gas? what is there in those sensors?
Based on different mechanisms like semiconductors, oxidation, catalytic, infrared, etc. The standard cells present in the sensor is matching to the input air which goes in it and if against the calibarated value, its raising alarm...You may get further details from the attachments...
4. How it is calibrated?
We have to refer the operational manual of individual detecotors for knowing the caliberation procedure...
I hope this may be helpful to you... Do let me know your comments...

Thank you for your answers.

Gas Detectors and Alarm Systems

It's supposed that the O2 range increased gas detectors show the value in mean time to raise the alarm/sound. I have used MSA type gas detectors on my site. Please let me know if you need more information.

Regards,

Dear Hansa,

First of all, sorry for being late. I missed out on replying to this thread. Raghu has already answered your query. The set point for the alarm is determined according to our requirements by the manufacturer. If it's 21% high alarm level for Oxygen, and in case the atmosphere has more than 21%, it will trigger an alarm and will only stop when the atmosphere returns to normal conditions, i.e., 21% or below.

Now, you may go through the attached manual for the Multi-gas Detector by Honeywell. You will find a lot of information regarding the gas detectors in it.

@Raghu: Thanks for your inputs in the thread. Keep sharing and keep up the pace.