Measuring sub-Femtoamp currents

[Guy Macon]

Mike Monett wrote:

I hoped for 10fA. 0.1fA would be golden.

OK, I give up. How? And how much thermal drift? Over what voltage range?
And what about cmmr? How much INL? What happens with ESD?

Doesn't help much if it needs -273C to run, and normal body capacitance
blows the inputs.

How to do this? Enquiring mind wants to know

Buy one of these:
http://www.keithley.com/products/currentvoltage/?mn=6430

or build something along these lines:
http://www.reed-electronics.com/tmworld/index.asp?layout=articlePrint&articleID=CA214124

--
Guy Macon <http://www.guymacon.com/>

 

[Ratch]

"Guy Macon" <http://www.guymacon.com/> wrote in message
news:11bv5g23kqs4gae@corp.supernews.com...

Mike Monett wrote:

I hoped for 10fA. 0.1fA would be golden.

OK, I give up. How? And how much thermal drift? Over what voltage range?
And what about cmmr? How much INL? What happens with ESD?

Doesn't help much if it needs -273C to run, and normal body capacitance
blows the inputs.

How to do this? Enquiring mind wants to know

Buy one of these:
http://www.keithley.com/products/currentvoltage/?mn=6430

Why doesn't that outfit display a price without having to register and
accept a cookie. They are probably afraid their prospective customers will
suffer sticker shock, so they first need to prepare them for trauma. Ratch

or build something along these lines:

http://www.reed-electronics.com/tmworld/index.asp?layout=articlePrint&articleID=CA214124

--
Guy Macon <http://www.guymacon.com/

 

[Winfield Hill]

Ratch wrote...

Guy Macon wrote ...
Mike Monett wrote:

I hoped for 10fA. 0.1fA would be golden.

OK, I give up. How? And how much thermal drift? Over what voltage
range? And what about cmmr? How much INL? What happens with ESD?
Doesn't help much if it needs -273C to run, and normal body
capacitance blows the inputs. How to do this? Enquiring mind
wants to know

Buy one of these:
http://www.keithley.com/products/currentvoltage/?mn=6430

Why doesn't that outfit display a price without having to register and
accept a cookie. They are probably afraid their prospective customers
will suffer sticker shock, so they first need to prepare them for trauma.

One can always hang out on eBay for a while and outbid me for a 642.


--
Thanks,
- Win

 

[John Larkin]

On Thu, 30 Jun 2005 21:00:08 -0500, "Ratch" <Watchit@comcast.net>
wrote:

"Guy Macon" <http://www.guymacon.com/> wrote in message
news:11bv5g23kqs4gae@corp.supernews.com...


Mike Monett wrote:

I hoped for 10fA. 0.1fA would be golden.

OK, I give up. How? And how much thermal drift? Over what voltage range?
And what about cmmr? How much INL? What happens with ESD?

Doesn't help much if it needs -273C to run, and normal body capacitance
blows the inputs.

How to do this? Enquiring mind wants to know

Buy one of these:
http://www.keithley.com/products/currentvoltage/?mn=6430

Why doesn't that outfit display a price without having to register and
accept a cookie. They are probably afraid their prospective customers will
suffer sticker shock, so they first need to prepare them for trauma. Ratch

Their model 2000 bench DVM is great... just over $1000.

John