Help Carbumeter

[Guest 49 plymouth]

Hi today I found this Elliott Carbumeter I would like to try get it going anybody know anything about it. I think it messures fuel air ratio at the tail pipe?

[28 Chrysler]

Can you get a photo of the tag and the internal components ?

[Guest 49 plymouth]

Thanks for the interest

[Kell]

Did you ever figure out how tis unit worked?  I have on as well

[padgett]

Just an air-fuel exhaust sniffer (not for catalysts) the scale and mention of a hose is the giveaway. I may have a more recent one "somewhere" (haven't seen for a few decades).

[mike6024]

I believe it measures the "Lambda coefficient" like the oxygen sensor does in a modern fuel injection system. How much excess oxygen is in the exhaust.

 

http://en.wikipedia.org/wiki/Exhaust_gas_analyzer

 

Lambda coefficient measurement
Main article: AFR sensor
The presence of oxygen in the exhaust gases indicates that the combustion of the mixture was not perfect, resulting in contaminant gases. Thus measuring the proportion of oxygen in the exhaust gases of these engines can monitor and measure these emissions. This measurement is performed in the MOT test through Lambda coefficient measurement.

The Lambda coefficient (λ) is obtained from the relationship between air and gasoline involved in combustion of the mixture. It is a measure of the efficiency of the gasoline engine by measuring the percentage of oxygen in the exhaust.

When gasoline engines operate with a stoichiometric mixture of 14.7: 1 the value of LAMBDA (λ) is "1".

Mixing ratio = weight of fuel / weight of air

- Expressed as mass ratio: 14.7 kg of air per 1 kg. of fuel.
- Expressed as volume ratio: 10,000 liters of air per 1 liter of fuel.
With this relationship theoretically a complete combustion of gasoline is achieved and greenhouse gas emissions would be minimal. The coefficient is defined as Lambda coefficient

If Lambda > 1 = lean mixture, excess of air. If Lambda < 1 = rich mixture, excess of gasoline.

A lean mixture contains an excess of oxygen. The surplus oxygen will react with nitrogen to NOx (Oxides of nitrogen), if the temperature is high enough (around 1600°C) for enough time to permit so.
A rich mixture contains a deficit of oxygen. This makes it impossible for all fuel to combust completely to carbon dioxide and water vapour. Hence, some fuel will remain as a hydrocarbon (HC), or it will react only to carbon monoxide (CO). The carbon monoxide concentration in exhaust gases is closely related, and almost proportional to the air fuel ratio in the rich regions. It is, therefore, of great value when tuning an engine.
Carbon dioxide emitted is theoretically directly proportional to the fuel consumed at a given and constant air fuel ratio. Less carbon dioxide will be emitted per litre of fuel if λ < 1, since some fuel won't be able to combust completely.

[padgett]

Little lambs eat ivy.

[mike6024]

you will need to connect a hose and metal tube to it, to function like tailpipe probe.

 

 

[Rusty_OToole]

A kid'll eat ivy too.

[bryankazmer]

that explains Lambda ratio, but not what the meter is actually measuring.  Interesting gizmo.  I think it measures thermal conductivity of the exhaust, which would change with composition