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US $768.00
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How to create a 100ppm amosphere in a container?
I want to create an atmosphere of 100 ppm & 300 ppm of unleaded fuel/air - to calibrate a gas sensor/circuit.
Can anyone say simply how to do this. What I know of chemistry is limited, but know how to safely handle unleaded (firefighter training).
I picture an answer like x number of eyedropper drops, into a container of y litres. If it' is more accurate to use cc's, this is fine as I will use a small glass syringe to measure it. When the drop or two of petrol is in the container I was intending to sit the container in hot water to vaporise it.
I can accept a container size of an odd amount by using a larger glass one and adding water until the correct volume was left (so an answer of 0.874L would be totally acceptable and useful).
This is well below the explosive point of the vapor (about 10% of LEVL), and using industrial UL spec'd petrol gas sensing detectors - theres no risk of an explosion.
A small proper explosionproof fan will circulate the vapor.
Anyone?
It would be very simple to figure...if you know the chemical composition of the 'fuel'. I found a website that gives the molecular wieght as 108 amu, so I will use this wieght.
If you wiegh out 108 grams of gas, this is the equivelent on a molecular level to 22.4 L of air (if both are in gaseous form, at 0 degrees C and 1 atm of pressure, then they have the same amount of molecules). Having the air at 0 degrees is probably not realistic, so you will have to adjust for different temp/pressure. However, if the temp was room temperature, this would only affect the results by a factor of about 10 percent. This would mean, for a 1 to 3 mix, you would need about 1 gram of gas for every .2 L of air. That should be easy enough to mix up.
Density is about .75g/ml, so for every 10 ml of gas that you measure, you will get 7.5 grams. Mix it up as large a batch as you need, test it, then tweak it.
Have a good one.
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