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Guest

Fri Dec 28, 2018 4:45 pm   



pcdhobbs wrote
Quote:
Not really. The patent talks about photocurrent, for one thing, and for another, using the same type of ambient light sensing
photodiode for both the ambient and display brightness is a nice intuitive idea that also makes physical sense.

Besides, a 2.5 mm square PD is easy to mount right next to the ambient light sensor for the ambient reading (ensuring good
tracking) and easy to tape upside-down on top of a full-brightness area on the display to measure its brightness in a repeatable
way.

Photometer heads are bigger and clunkier, so that would be hard to do.

Cheers

Phil Hobbs


No idea what it is all about,
but if you want to track display brigtness versus background brightness,
and that is likely into the direction you look,
then simpe video camera, processing, mask out background,
mask out bright spot (brightesr spot perhasp) in display,
compare if it tracks or not.
|
[]() || |
cam display |
| background
tronix

?

Phil Hobbs
Guest

Fri Dec 28, 2018 4:45 pm   



On 12/28/18 9:51 AM, 698839253X6D445TD_at_nospam.org wrote:
Quote:
pcdhobbs wrote
Not really. The patent talks about photocurrent, for one thing, and for another, using the same type of ambient light sensing
photodiode for both the ambient and display brightness is a nice intuitive idea that also makes physical sense.

Besides, a 2.5 mm square PD is easy to mount right next to the ambient light sensor for the ambient reading (ensuring good
tracking) and easy to tape upside-down on top of a full-brightness area on the display to measure its brightness in a repeatable
way.

Photometer heads are bigger and clunkier, so that would be hard to do.

Cheers

Phil Hobbs

No idea what it is all about,
but if you want to track display brigtness versus background brightness,
and that is likely into the direction you look,
then simpe video camera, processing, mask out background,
mask out bright spot (brightesr spot perhasp) in display,
compare if it tracks or not.
|
[]() || |
cam display |
| background
tronix

?


;)

As I've said for thirty years, "A software guy thinks that the way to do
any optical thing is to point a camera at it and crunch the daylights
out of the resulting crappy data."

You can make nice linear measurements with the right camera, but
ordinary video cameras have so much auto aperture, auto integration
time, gamma correction, colour gamut optimization, yadda yadda, that
linear measurements don't happen by accident.

Photodiodes for me all the way.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

George Herold
Guest

Fri Dec 28, 2018 6:45 pm   



On Friday, December 28, 2018 at 12:11:09 PM UTC-5, 69883925...@nospam.org wrote:
Quote:
Phil Hobbs in fear of cameras
On 12/28/18 9:51 AM, 698839253X6D445TD_at_nospam.org wrote:
pcdhobbs wrote
Not really. The patent talks about photocurrent, for one thing, and for another, using the same type of ambient light
sensing
photodiode for both the ambient and display brightness is a nice intuitive idea that also makes physical sense.

Besides, a 2.5 mm square PD is easy to mount right next to the ambient light sensor for the ambient reading (ensuring good
tracking) and easy to tape upside-down on top of a full-brightness area on the display to measure its brightness in a
repeatable
way.

Photometer heads are bigger and clunkier, so that would be hard to do.

Cheers

Phil Hobbs

No idea what it is all about,
but if you want to track display brigtness versus background brightness,
and that is likely into the direction you look,
then simpe video camera, processing, mask out background,
mask out bright spot (brightesr spot perhasp) in display,
compare if it tracks or not.
|
[]() || |
cam display |
| background
tronix

?


;)

As I've said for thirty years, "A software guy thinks that the way to do
any optical thing is to point a camera at it and crunch the daylights
out of the resulting crappy data."

Software guy?
I designed my first video camera in 1968.
That got me an engineering job in the national network.

Tell me about cameras,.,


You can make nice linear measurements with the right camera, but
ordinary video cameras have so much auto aperture, auto integration
time, gamma correction, colour gamut optimization, yadda yadda, that
linear measurements don't happen by accident.

Bull.

Take a 30 $ or so CMOS, and process the data.
1% 40dB dynamic range is the minimum you should get with reasonable lighting.

Bit more expensive CCD camera and take a few screenshots (per second?) in HD.


Photodiodes for me all the way.

That is your choice, those cameras have more than one :-)

Think about is, few hundred thousand photo diodes all exactly the same,
doing the work for you looking at your whateveritis.

Software did not exist when I started with video.
Neither did sensor chips,
And even then with plumbicons we could do what you talk about now,
in color.

:-)


Both have their uses. When I was at the FEL (free electron laser)
we kept vidicons alive for imaging the electron beam. Other
camera's died a quick death in the harsh radiation environment.

George H.

Phil Hobbs
Guest

Fri Dec 28, 2018 6:45 pm   



On 12/28/18 12:11 PM, 698839253X6D445TD_at_nospam.org wrote:
Quote:
Phil Hobbs in fear of cameras
On 12/28/18 9:51 AM, 698839253X6D445TD_at_nospam.org wrote:
pcdhobbs wrote
Not really. The patent talks about photocurrent, for one thing, and for another, using the same type of ambient light
sensing
photodiode for both the ambient and display brightness is a nice intuitive idea that also makes physical sense.

Besides, a 2.5 mm square PD is easy to mount right next to the ambient light sensor for the ambient reading (ensuring good
tracking) and easy to tape upside-down on top of a full-brightness area on the display to measure its brightness in a
repeatable
way.

Photometer heads are bigger and clunkier, so that would be hard to do.

Cheers

Phil Hobbs

No idea what it is all about,
but if you want to track display brigtness versus background brightness,
and that is likely into the direction you look,
then simpe video camera, processing, mask out background,
mask out bright spot (brightesr spot perhasp) in display,
compare if it tracks or not.
|
[]() || |
cam display |
| background
tronix

?


;)

As I've said for thirty years, "A software guy thinks that the way to do
any optical thing is to point a camera at it and crunch the daylights
out of the resulting crappy data."

Software guy?
I designed my first video camera in 1968.
That got me an engineering job in the national network.

Tell me about cameras,.,


You can make nice linear measurements with the right camera, but
ordinary video cameras have so much auto aperture, auto integration
time, gamma correction, colour gamut optimization, yadda yadda, that
linear measurements don't happen by accident.

Bull.

Take a 30 $ or so CMOS, and process the data.
1% 40dB dynamic range is the minimum you should get with reasonable lighting.


40 dB is pathetic.

Cheers

Phil Hobbs


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com


Guest

Fri Dec 28, 2018 6:45 pm   



Phil Hobbs in fear of cameras
Quote:
On 12/28/18 9:51 AM, 698839253X6D445TD_at_nospam.org wrote:
pcdhobbs wrote
Not really. The patent talks about photocurrent, for one thing, and for another, using the same type of ambient light
sensing
photodiode for both the ambient and display brightness is a nice intuitive idea that also makes physical sense.

Besides, a 2.5 mm square PD is easy to mount right next to the ambient light sensor for the ambient reading (ensuring good
tracking) and easy to tape upside-down on top of a full-brightness area on the display to measure its brightness in a
repeatable
way.

Photometer heads are bigger and clunkier, so that would be hard to do.

Cheers

Phil Hobbs

No idea what it is all about,
but if you want to track display brigtness versus background brightness,
and that is likely into the direction you look,
then simpe video camera, processing, mask out background,
mask out bright spot (brightesr spot perhasp) in display,
compare if it tracks or not.
|
[]() || |
cam display |
| background
tronix

?


;)

As I've said for thirty years, "A software guy thinks that the way to do
any optical thing is to point a camera at it and crunch the daylights
out of the resulting crappy data."


Software guy?
I designed my first video camera in 1968.
That got me an engineering job in the national network.

Tell me about cameras,.,


Quote:
You can make nice linear measurements with the right camera, but
ordinary video cameras have so much auto aperture, auto integration
time, gamma correction, colour gamut optimization, yadda yadda, that
linear measurements don't happen by accident.


Bull.

Take a 30 $ or so CMOS, and process the data.
1% 40dB dynamic range is the minimum you should get with reasonable lighting.

Bit more expensive CCD camera and take a few screenshots (per second?) in HD.


>Photodiodes for me all the way.

That is your choice, those cameras have more than one :-)

Think about is, few hundred thousand photo diodes all exactly the same,
doing the work for you looking at your whateveritis.

Software did not exist when I started with video.
Neither did sensor chips,
And even then with plumbicons we could do what you talk about now,
in color.

:-)

George Herold
Guest

Fri Dec 28, 2018 6:45 pm   



On Friday, December 28, 2018 at 10:14:41 AM UTC-5, Phil Hobbs wrote:
Quote:
On 12/28/18 9:51 AM, 698839253X6D445TD_at_nospam.org wrote:
pcdhobbs wrote
Not really. The patent talks about photocurrent, for one thing, and for another, using the same type of ambient light sensing
photodiode for both the ambient and display brightness is a nice intuitive idea that also makes physical sense.

Besides, a 2.5 mm square PD is easy to mount right next to the ambient light sensor for the ambient reading (ensuring good
tracking) and easy to tape upside-down on top of a full-brightness area on the display to measure its brightness in a repeatable
way.

Photometer heads are bigger and clunkier, so that would be hard to do.

Cheers

Phil Hobbs

No idea what it is all about,
but if you want to track display brigtness versus background brightness,
and that is likely into the direction you look,
then simpe video camera, processing, mask out background,
mask out bright spot (brightesr spot perhasp) in display,
compare if it tracks or not.
|
[]() || |
cam display |
| background
tronix

?


;)

As I've said for thirty years, "A software guy thinks that the way to do
any optical thing is to point a camera at it and crunch the daylights
out of the resulting crappy data."

You can make nice linear measurements with the right camera, but
ordinary video cameras have so much auto aperture, auto integration
time, gamma correction, colour gamut optimization, yadda yadda, that
linear measurements don't happen by accident.

Photodiodes for me all the way.

Cheers

Phil Hobbs

Hi Phil. (I trust everyone had a merry Christmas) DMM in current mode and
a photodiode is my fav poor mans light meter, very simple.
I've got an older fluke 87 in the lab. I thought it had a 10 uA scale and
minimum resolution of 1 nA... but I'm not in the lab this week and may be
mistaken. We've also go a new keysight DMM... but again that will have
to wait till next week for me to check. Is there any time crunch?

George H.
(ps unrelated, we got our first robot (Roomba 690) for xmas..
fun... though it can spend a lot of time underneath the couch
trying to find a way out.)
(Or maybe it is doing something else under there :^)

GH
Quote:

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com



Guest

Sat Dec 29, 2018 4:45 am   



On Friday, December 28, 2018 at 9:38:14 AM UTC-5, pcdh...@gmail.com wrote:
Quote:
Hey, EEVblog is a widely-known brand name by now.
 You can safely assert that to a jury.

Sure, every pipe fitter and school teacher knows ol' Squeaky Dave. ;)

Cheers

Phil Hobbs


I resemble that remark.

I was wondering Phil, what is your username on EEVBLOG? Care to tell? Smile


Steve


Guest

Sat Dec 29, 2018 7:45 am   



>I was wondering Phil, what is your username on EEVBLOG?  Care to tell? Smile

I don't recall ever posting there, though I may have long ago. I don't like proprietary platforms, for one thing.

Cheers

Phil Hobbs


Guest

Sat Dec 29, 2018 9:45 am   



Phil Hobbs
Quote:
40 dB is pathetic.


In case dynamic range matters for whateveritis you are doing:
https://www.photometrics.com/resources/learningzone/dynamicrange.php

I was impressed some years ago by BW shots from the air of ships spilling oil,
a near 16 bit dynamic range, and the display software just a 256 bits sliding window on it
could read the ship name in the dark.

https://www.pco.de/company/whats-new/news/article/high-dynamic-range-imaging-with-scmos-scientific-cmos/
Download the white paper;
http://www.pco.de/fileadmin/user_upload/db/download/scmos_white_paper_2mb_01.pdf

A lot has happened and is happening in that field.
Maybe you are re-inventing the wheel?
That may byte you in legal cases.

Hope this helps.

George Herold
Guest

Sat Dec 29, 2018 5:45 pm   



On Saturday, December 29, 2018 at 3:36:51 AM UTC-5, 69883925...@nospam.org wrote:
Quote:
Phil Hobbs
40 dB is pathetic.


In case dynamic range matters for whateveritis you are doing:
https://www.photometrics.com/resources/learningzone/dynamicrange.php

I was impressed some years ago by BW shots from the air of ships spilling oil,
a near 16 bit dynamic range, and the display software just a 256 bits sliding window on it
could read the ship name in the dark.

https://www.pco.de/company/whats-new/news/article/high-dynamic-range-imaging-with-scmos-scientific-cmos/
Download the white paper;
http://www.pco.de/fileadmin/user_upload/db/download/scmos_white_paper_2mb_01.pdf

A lot has happened and is happening in that field.
Maybe you are re-inventing the wheel?
That may byte you in legal cases.

Hope this helps.


I'm guessing you haven't read Phil's book.
https://www.wiley.com/en-us/Building+Electro+Optical+Systems%3A+Making+It+all+Work%2C+2nd+Edition-p-9780470402290

(I've only read the first edition.)

Lotsa good stuff.
George H.


Guest

Sat Dec 29, 2018 5:45 pm   



George Herold wrote
>I'm guessing you haven't read Phil's book.

You guessed right.


>(I've only read the first edition.)

Have not read the art of tronics either.


>Lotsa good stuff.

smoking is bad for yer health,


Some things are amusing here.
like the thread about so many pins and secure....

When I write code I do not bother with 'secure' as I know there could be someone like me
somewhere who for some reason has a reason to hack it and will.

I think P.H. has camera fear ;-)

But at least he did read up on it a bit.

There is that old joke, how to detect intelligent life on some alien planet?
Put a camera there and it will jump in front of it...
http://panteltje.com/panteltje/space/mars/easthills-bunny.jpg

George Herold
Guest

Sat Dec 29, 2018 5:45 pm   



On Saturday, December 29, 2018 at 11:06:42 AM UTC-5, 69883925...@nospam.org wrote:
Quote:
George Herold wrote
I'm guessing you haven't read Phil's book.

You guessed right.


(I've only read the first edition.)

Have not read the art of tronics either.

Oh, you should definitely check out the third edition,
it's chock full of useful information. (Graph of
CMRR vs freq. for a bunch of instrument amps.)
I think 1/2 the circuits I use started as hacks from something
in AoE.

George H.
Quote:


Lotsa good stuff.

smoking is bad for yer health,


Some things are amusing here.
like the thread about so many pins and secure....

When I write code I do not bother with 'secure' as I know there could be someone like me
somewhere who for some reason has a reason to hack it and will.

I think P.H. has camera fear ;-)

But at least he did read up on it a bit.

There is that old joke, how to detect intelligent life on some alien planet?
Put a camera there and it will jump in front of it...
http://panteltje.com/panteltje/space/mars/easthills-bunny.jpg



Guest

Sat Dec 29, 2018 7:45 pm   



George Herold wrote
Quote:
On Saturday, December 29, 2018 at 11:06:42 AM UTC-5, 69883925...@nospam.org wrote:
Have not read the art of tronics either.

Oh, you should definitely check out the third edition,
it's chock full of useful information. (Graph of
CMRR vs freq. for a bunch of instrument amps.)


For a moment I thought 'cosmic microwave background', but then something with commie modes more likely.


Quote:
I think 1/2 the circuits I use started as hacks from something
in AoE.


In these days google shows a lot, including circuits.
I do remember I came across a page from that book in google once.


I stopped reading tronics magazines around 2000 ...

Books is a bit ancient technology, really ;-)

In the school where I learned formal 'tronics we had no books, but teachers made stencils.
Always up to date that way, of course the teachers were not alway up to date,
One day a guy in my class asked"
'Sir, what is exactly a complementary pair?
He got almost kicked out as teacher thought it was a sex joke Wink
It took the whole class to convince the teacher it was a real question.

Transistors were kind of new,,, well for some anyways.

The times, they are a-changin'.
https://www.google.nl/search?dcr=0&source=hp&ei=YbYnXNv5CZGjwALP76_QAg&q=bob+dylan+the+times+they+are+changin+lyrics&oq=bof+dylan+the+times+they+are+changing&gs_l=psy-ab.1.1.0i13j0i13i10j0i13j0i13i10i30l3j0i8i13i10i30l3.2809.10803..15539...0.0..3.410.9723.0j8j17j11j1......0....1..gws-wiz.....0..0j0i10j0i8i13i30.W1lcyk5Q8UI

Phil Hobbs
Guest

Sun Dec 30, 2018 2:45 am   



On 12/28/18 11:49 AM, George Herold wrote:
Quote:
On Friday, December 28, 2018 at 10:14:41 AM UTC-5, Phil Hobbs wrote:
On 12/28/18 9:51 AM, 698839253X6D445TD_at_nospam.org wrote:
pcdhobbs wrote
Not really. The patent talks about photocurrent, for one thing,
and for another, using the same type of ambient light sensing
photodiode for both the ambient and display brightness is a
nice intuitive idea that also makes physical sense.

Besides, a 2.5 mm square PD is easy to mount right next to the
ambient light sensor for the ambient reading (ensuring good
tracking) and easy to tape upside-down on top of a
full-brightness area on the display to measure its brightness
in a repeatable way.

Photometer heads are bigger and clunkier, so that would be hard
to do.

Cheers

Phil Hobbs

No idea what it is all about, but if you want to track display
brigtness versus background brightness, and that is likely into
the direction you look, then simpe video camera, processing, mask
out background, mask out bright spot (brightesr spot perhasp) in
display, compare if it tracks or not. | []() || | cam
display | | background tronix

?


;)

As I've said for thirty years, "A software guy thinks that the way
to do any optical thing is to point a camera at it and crunch the
daylights out of the resulting crappy data."

You can make nice linear measurements with the right camera, but
ordinary video cameras have so much auto aperture, auto
integration time, gamma correction, colour gamut optimization,
yadda yadda, that linear measurements don't happen by accident.

Photodiodes for me all the way.

Cheers

Phil Hobbs
Hi Phil. (I trust everyone had a merry Christmas) DMM in current
mode and a photodiode is my fav poor mans light meter, very simple.
I've got an older fluke 87 in the lab. I thought it had a 10 uA
scale and minimum resolution of 1 nA... but I'm not in the lab this
week and may be mistaken.


My 1988-vintage Fluke 87 is on the sick list at the moment. :(

I bought it for a bit of moonlighting while I was a postdoc at IBM
Watson--I had a small gig involving a gizmo to fuse medical waste into
compact blocks to prevent it from washing up on East Coast beaches after
being dumped by mob-controlled 'waste disposal' outfits. The situation
didn't last long, so the opportunity didn't either. Interesting problem
though.


Quote:
We've also go a new keysight DMM... but again that will have to wait
till next week for me to check. Is there any time crunch?


Nah, I got another Keithley 177 for $46 including shipping. It has 1 nA
resolution, which is fine for this job. Thanks though.

Quote:

George H. (ps unrelated, we got our first robot (Roomba 690) for
xmas.. fun... though it can spend a lot of time underneath the couch
trying to find a way out.) (Or maybe it is doing something else under
there :^)


Fun. We got one of those some time back for a friend with limited
mobility. It was fun to watch for awhile but was not reliable enough
for that sort of situation.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

George Herold
Guest

Sun Dec 30, 2018 5:45 am   



On Saturday, December 29, 2018 at 7:49:13 PM UTC-5, Phil Hobbs wrote:
Quote:
On 12/28/18 11:49 AM, George Herold wrote:
On Friday, December 28, 2018 at 10:14:41 AM UTC-5, Phil Hobbs wrote:
On 12/28/18 9:51 AM, 698839253X6D445TD_at_nospam.org wrote:
pcdhobbs wrote
Not really. The patent talks about photocurrent, for one thing,
and for another, using the same type of ambient light sensing
photodiode for both the ambient and display brightness is a
nice intuitive idea that also makes physical sense.

Besides, a 2.5 mm square PD is easy to mount right next to the
ambient light sensor for the ambient reading (ensuring good
tracking) and easy to tape upside-down on top of a
full-brightness area on the display to measure its brightness
in a repeatable way.

Photometer heads are bigger and clunkier, so that would be hard
to do.

Cheers

Phil Hobbs

No idea what it is all about, but if you want to track display
brigtness versus background brightness, and that is likely into
the direction you look, then simpe video camera, processing, mask
out background, mask out bright spot (brightesr spot perhasp) in
display, compare if it tracks or not. | []() || | cam
display | | background tronix

?


;)

As I've said for thirty years, "A software guy thinks that the way
to do any optical thing is to point a camera at it and crunch the
daylights out of the resulting crappy data."

You can make nice linear measurements with the right camera, but
ordinary video cameras have so much auto aperture, auto
integration time, gamma correction, colour gamut optimization,
yadda yadda, that linear measurements don't happen by accident.

Photodiodes for me all the way.

Cheers

Phil Hobbs
Hi Phil. (I trust everyone had a merry Christmas) DMM in current
mode and a photodiode is my fav poor mans light meter, very simple.
I've got an older fluke 87 in the lab. I thought it had a 10 uA
scale and minimum resolution of 1 nA... but I'm not in the lab this
week and may be mistaken.

My 1988-vintage Fluke 87 is on the sick list at the moment. Sad

Huh, what's wrong? Mine had a flaky input and a ~$20 new connector
fixed it.
Quote:

I bought it for a bit of moonlighting while I was a postdoc at IBM
Watson--I had a small gig involving a gizmo to fuse medical waste into
compact blocks to prevent it from washing up on East Coast beaches after
being dumped by mob-controlled 'waste disposal' outfits. The situation
didn't last long, so the opportunity didn't either. Interesting problem
though.


We've also go a new keysight DMM... but again that will have to wait
till next week for me to check. Is there any time crunch?

Nah, I got another Keithley 177 for $46 including shipping. It has 1 nA
resolution, which is fine for this job. Thanks though.


George H. (ps unrelated, we got our first robot (Roomba 690) for
xmas.. fun... though it can spend a lot of time underneath the couch
trying to find a way out.) (Or maybe it is doing something else under
there :^)

Fun. We got one of those some time back for a friend with limited
mobility. It was fun to watch for awhile but was not reliable enough
for that sort of situation.

I just want it to try and keep the pet hair under control, so far it
does that, but needs to be cleaned before each run.

George H.
Quote:

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com


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