Questions tagged [gas]
The gas tag has no usage guidance.
19
questions
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0answers
22 views
H2S Sensor with 1 PPB Lower Detection Limit
We're trying to create an IoT device that can detect/mesaure H2S in ambient air with a
lower detection limit of 1 ppb or 0.001 ppm
However, checking Digikey and other similar suppliers, I haven't ...
0
votes
0answers
26 views
Surface oxidation rates in CO2 vs Nitrogen vs Air?
Is there a difference in surface oxidation and formation of electrical arcs on electrical contacts in ambient CO2 and N2 and Air? Can the surface oxidation difference be quantified?
1
vote
1answer
92 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
3answers
126 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 ...
-3
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1answer
199 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: ...
1
vote
1answer
79 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
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 ...
0
votes
1answer
409 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 ...
6
votes
1answer
5k 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 (...
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1answer
80 views
-2
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2answers
103 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
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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 ...
1
vote
0answers
488 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-...
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 ...
4
votes
1answer
149 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
...
-6
votes
1answer
423 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 ...
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 ...
4
votes
1answer
481 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.
