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Questions tagged [gas]

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6
votes
1answer
4k views

What (type of) sensor can detect odor of faeces?

"The Chemistry of the Smell of Toilets & Human Waste" has a really nice overview of the types of gases you want to detected if you're after building a toilet-clean-air detector. Hydrogen sulfide (...
4
votes
1answer
144 views

determining sensitivity of carbon monoxide sensor

i'm working with a alphasense CO-AF sensor & i need to find out the CO quantity in ppm . i referred to the data sheet of the device and i dont know how to convert the given sensitivity ...
4
votes
1answer
443 views

Why is it called a gas gauge?

Why are battery monitor ICs such as STC3115 (datasheet) called a gas gauge? This name seems pretty illogical and I was wondering the reasoning/story behind it.
2
votes
3answers
2k views

MQ-135 Gas Sensor Interface

I want to interface MQ-135 air quality gas sensor. Sensor have 5V output interface. However my mcu work at 3.3V. I can basically put a voltage divider. But sensor itself is a voltage divider with a ...
2
votes
2answers
1k views

Gas sensors for multiple gases

I have some questions about gas sensors: If I want to detect several gases at once, do I just need one sensor or will I need one sensor for each gas? How will I know which gas I am measuring? These ...
1
vote
3answers
110 views

Power plant cost accounting

For a 300 MW power plant, 14.5 MJ / kWh of heating capacity must be provided. For this you can use coal with a heating value (hW) of 29 MJ / kg and a price (P) of 35 € / t or gas with a calorific ...
1
vote
1answer
78 views

My gas sensor is stuck physically, how can I fix it? [closed]

I'm not sure if this is the right area, but it's a problem with one of my components physically. When I press on both sides, it doesn't come up. Is there any way that I can get this 'up' cosmetically ...
1
vote
1answer
86 views

MQ Gas sensors - can heater coil be run 24/7?

I am building a Hydrogen Sulphide gas detector for battery charging rooms using a MQ-136 sensor. I have searched everywhere for the answer to this question:- Can the sensor be powered continuously? I ...
1
vote
0answers
2k views

Are gas bubbles ok in Flooded lead acid battery charging?

I Have HBL power system's 2cell 4.2v lead acid battery which has capacity of 12Ah for C/ 100 and 9Ah for C/10. I found it in the rubbish and thought it may useful and in working condition.I ...
1
vote
0answers
418 views

Problem with biased circuit for oxygen sensor (SGX EC410)

I have designed a circuit for an SGX EC410 oxygen sensor by using these application note -PAGE 4, FIGURE 4 - (http://www.sgxsensortech.com/content/uploads/2014/08/A1A-EC_SENSORS_AN2-Design-of-...
0
votes
1answer
393 views

How to measure air quality (especially PM2.5) from distance (scanning like a LiDAR)? [closed]

I have a bit of experience in measuring PM2.5 (fine particles in the (ambient) air 2.5 micrometres or less in size) using PMS5003 sensor. This sensor uses laser, photodiode and the fact that the air ...
-2
votes
2answers
95 views

Conductivity of Different Gasses [closed]

Hey what is the most conductive gas that can be easily found. and will lowering the pressure increase the conductivity?
-2
votes
1answer
79 views

Gas Leakage Circuit [closed]

What Transistor should i use instead of SL100? thanks
-2
votes
1answer
65 views

GAS leakage circuit

i tried to simulate the circuit below with the Proteus 8 Professional , but i didn't find the SL100 transistor so i replaced it with BC547 , is it ok? and when i give the pin 4 high , the LED starts ...
-2
votes
2answers
1k views

Natural gas sensor to measure and keep track of the consumption?

I need to work on this project for a friend of mine for his small coffee shop, he needs to keep track of the natural gas consumption. So I was thinking, I can measure the pressure and calculate an ...
-3
votes
1answer
186 views

Using MQ-4 Sensor without heating [closed]

Is there any way to correctly measure increase of methane in the air using MQ-4 without heating (Not linking heater legs to GND and V). It is needed to save power. MQ-4 is methane sensor, datasheet: ...
-6
votes
1answer
339 views

How or where can I get a 120VAC to 3.3VAC power supply?

I'm using a safety gas valve (commonly found in household stoves) for a hobby project. The valve is rated for 3.3VAC, 3.6Amps. The problem is that AC-to-AC power supplies are quite rare, and I had no ...