Measuring µA

I am currently working on a project that monitors a bakery production line.

They use large commercial burners to heat the ovens. These burners utilise an ionisation detection system which creates 5-25µA.

My plan is to piggy back the lead from the ionisation probe and display this reading so the workers on the line can monitor the flame strength.

Could a resistor current/voltage transformer achieve this?

Cheers.

Normally, a piggy back arrangement can only be used when measuring voltages. Also a circuit that measures such small currents can easily be disturbed by additional circuitry. Unless you are very experienced, and have access to the design details of the detection system, I would not recommend attempting this.

That small a current would require amplification to be useable by an Arduino even if you could piggyback. As aarg has said, this is not practical.

Weedpharma

You need to piggyback the Arduino to the controller to which the probe connects.

HenrySCatt: My plan is to piggy back the lead from the ionisation probe and display this reading so the workers on the line can monitor the flame strength.

Are you sure that there is a relationship between the current and the flame strength?

I would have though that the ionisation probe was just used to give an indication of the presence/absence of the flame.

JohnLincoln: Are you sure that there is a relationship between the current and the flame strength?

I would have though that the ionisation probe was just used to give an indication of the presence/absence of the flame.

Hi yes the burner has a full sequence controller that measures between 5 and 15 µA.

If the probe gets dirty it knocks off. The idea is if the operators can see the current dropping into the 'danger zone' they can plan to stop the line rather than have it fail half way through the process.

I do clean them regularly but its just a question the MD has asked.

Oh and Honeywell TMI controllers have 5 LED's that show the ionisation strength so it can be done.... but how.... I don't know!!!!

Cheers all for your posts anyway. Food for thought...

JohnLincoln: Are you sure that there is a relationship between the current and the flame strength?

I would have though that the ionisation probe was just used to give an indication of the presence/absence of the flame.

Yes, now i'm no fancy scientist but the principle as i understand it the flame excites the atoms and particles and stuff in the atmospheric gasses which causes them to move very quickly. When they come into contact with the probe it creates a tiny current..... µA amounts.... which is what I want to read.

When I put my meter onto µA and clip one lead onto the probe and the other onto the probe lead I can read it and diagnose potential faults.