Electrometer batteries???

  • Thread starter George R. Gonzalez
  • Start date
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George R. Gonzalez

Guest
HI, I have a clean-looking Keithley 600B electrometer.

Problem is, no manual, and no clue what kind of batteries it needs.

There's a small battery holder that maybe could hold a small old-style
(1/3 AA) mercury battery. And FOUR clips that would fit your basic 9V
006P, except the holding bracket for them is about 8 times too
volume-iffic.

Any hints appreciated.

Reagards,

George
 
George:

I also have a 600B. The four batteries are indeed 9V,
but a very early model. They are 1 3/8" x 1 3/8" x
x 2 5/8". I kept one just for the heck of it
that I removed from my original meter. It is a
zinc carbon EVEREADY no. 246. (NEDA 1602) Don't known
if still available, but I would guess if they are
you would pay an arm and leg for them. I use regular
size 9 V alk. batteries with reasonable battery life.

You guessed correctly the small cylindrical battery
is indeed a mercury cell (1.35 volts if I remember).
I kept it also but can't seem to locate it right now.
Good luck finding a replacement. I went looking for one
several years ago and found that it is illegal (Federal
Environmental Law) to sell or even import batteries
containing mercury. Never found a source. If you do
let me know. Since it is used for the linear
Ohms scale using a regular alkaline battery will make
the scales significantly inaccurate. I think the
drain is extremely low so I thought about designing
a voltage regulator circuit running off a higher voltage
battery but never got around to doing it.

The 600B is a nice meter. I picked mine up for $10 at
Dayton HF one year. Don't have a schematic though. If
you get a lead on that let me know.

Dave Woolf - K8RSP
(If replying directly remove NOSPAM from above address)

George R. Gonzalez wrote:
HI, I have a clean-looking Keithley 600B electrometer.

Problem is, no manual, and no clue what kind of batteries it needs.

There's a small battery holder that maybe could hold a small old-style
(1/3 AA) mercury battery. And FOUR clips that would fit your basic 9V
006P, except the holding bracket for them is about 8 times too
volume-iffic.

Any hints appreciated.

Reagards,

George
Click to expand...
 
Dave Woolf wrote:
George:

I also have a 600B. The four batteries are indeed 9V,
but a very early model. They are 1 3/8" x 1 3/8" x
x 2 5/8". I kept one just for the heck of it
that I removed from my original meter. It is a
zinc carbon EVEREADY no. 246. (NEDA 1602) Don't known
if still available, but I would guess if they are
you would pay an arm and leg for them. I use regular
size 9 V alk. batteries with reasonable battery life.

You guessed correctly the small cylindrical battery
is indeed a mercury cell (1.35 volts if I remember).
I kept it also but can't seem to locate it right now.
Good luck finding a replacement. I went looking for one
several years ago and found that it is illegal (Federal
Environmental Law) to sell or even import batteries
containing mercury. Never found a source. If you do
let me know. Since it is used for the linear
Ohms scale using a regular alkaline battery will make
the scales significantly inaccurate. I think the
drain is extremely low so I thought about designing
a voltage regulator circuit running off a higher voltage
battery but never got around to doing it.

The 600B is a nice meter. I picked mine up for $10 at
Dayton HF one year. Don't have a schematic though. If
you get a lead on that let me know.

Dave Woolf - K8RSP
(If replying directly remove NOSPAM from above address)

George R. Gonzalez wrote:
HI, I have a clean-looking Keithley 600B electrometer.

Problem is, no manual, and no clue what kind of batteries it needs.

There's a small battery holder that maybe could hold a small old-style
(1/3 AA) mercury battery. And FOUR clips that would fit your basic 9V
006P, except the holding bracket for them is about 8 times too
volume-iffic.

Any hints appreciated.

Reagards,

George
Click to expand...
Try a Zinc-Air battery.
My reference book sez "once activated, the voltage stabilizes between
1.40 and 1.45V. Drawing discharge current quickly lowers the voltage to
1.30 volts..".
So, maybe, one could start with an activated zinc-air cell and put a
calibrated load for a fixed (timed) period - just enough to result in a
no load voltage of 1.35V.
The next question would be how stable and for how long that voltage
remains.

Another possible solution, with better chance of stable long-term
voltage: a silver-oxide cell opposing a lithium cell (3.0V-1.6V=1.4V).
 
On 7 Sep 2004 06:47:05 -0700 grg2@comcast.net (George R. Gonzalez)
wrote:

HI, I have a clean-looking Keithley 600B electrometer.

Problem is, no manual, and no clue what kind of batteries it needs.

There's a small battery holder that maybe could hold a small old-style
(1/3 AA) mercury battery. And FOUR clips that would fit your basic 9V
006P, except the holding bracket for them is about 8 times too
volume-iffic.
Click to expand...
It originally took 2 mercury D-cells on top, and 2 22 (or were they
28V batteries beside the D-cells.

Down on the side there are indeed 4 9V transistor batteries.

I have one of these, as well as a manual. When they are working, they
are nice units. I'm trying to visualize how these are held, but I
can't recall exactly. I don't recall them looking like the holders
were too big.

Email me directly and remind me to look at my 600B and the manual.

-
-----------------------------------------------
Jim Adney jadney@vwtype3.org
Madison, WI 53711 USA
-----------------------------------------------
 
Jim Adney wrote...
George R. Gonzalez wrote:

HI, I have a clean-looking Keithley 600B electrometer.
Problem is, no manual...

Email me directly and remind me to look at my 600B and the manual.
-
-----------------------------------------------
Jim Adney jadney@vwtype3.org
Madison, WI 53711 USA
-----------------------------------------------
Click to expand...
Jim, I'd very much like to look at your 600B manual, or at least
the schematic page.


--
Thanks,
- Win

(email: use hill_at_rowland-dotties-org for now)
 
On 9 Sep 2004 18:55:18 -0700 Winfield Hill
<Winfield_member@newsguy.com> wrote:

Jim Adney wrote...

George R. Gonzalez wrote:

HI, I have a clean-looking Keithley 600B electrometer.
Problem is, no manual...

Email me directly and remind me to look at my 600B and the manual.

Jim, I'd very much like to look at your 600B manual, or at least
the schematic page.
Click to expand...
Like most multimeter schematics, it's pretty hard to follow because of
all the multipole switch contacts, but it can be done. If either of
you want a copy just email me your address and I'll Xerox one for you.
I may have more than one version of the manual, so let me know if
you're looking for a particular serial number.

I also have replacement subminiature tubes for these, as well as a
circuit and method for matching them.

I've resurrected several of these, and their AC powered mates, over
the years.

-
-----------------------------------------------
Jim Adney jadney@vwtype3.org
Madison, WI 53711 USA
-----------------------------------------------
 
"Winfield Hill" <Winfield_member@newsguy.com> schrieb im Newsbeitrag
news:chr1i602fco@drn.newsguy.com...
Jim, I'd very much like to look at your 600B manual, or at least
the schematic page.
Click to expand...
it is downloadable from www.keithley.com ...
But I have not found Infos about any Battery for the 610B.

Rgds
Achin
 
Jim Adney wrote...
... If either of you want a copy just email me your address and
I'll Xerox one for you.

I also have replacement subminiature tubes for these, as well as
a circuit and method for matching them. I've resurrected several
of these, and their AC powered mates, over the years.
Click to expand...
Thanks, I got the manual from Keithley's website. I have my
technician tear these apart for the teflon switches and Gig-ohm
resistors, but he did save some of the miniature tube assemblies.


--
Thanks,
- Win

(email: use hill_at_rowland-dotties-org for now)
 
"Dave Woolf" <NOSPAMdwoolf@worldnet.att.net> wrote in message
news:413E65EC.9040907@worldnet.att.net...
George:

I also have a 600B. The four batteries are indeed 9V,
but a very early model. They are 1 3/8" x 1 3/8" x
x 2 5/8". I kept one just for the heck of it
that I removed from my original meter. It is a
zinc carbon EVEREADY no. 246. (NEDA 1602) Don't known
if still available, but I would guess if they are
you would pay an arm and leg for them. I use regular
size 9 V alk. batteries with reasonable battery life.

You guessed correctly the small cylindrical battery
is indeed a mercury cell (1.35 volts if I remember).
I kept it also but can't seem to locate it right now.
Good luck finding a replacement. I went looking for one
several years ago and found that it is illegal (Federal
Environmental Law) to sell or even import batteries
containing mercury. Never found a source. If you do
let me know. Since it is used for the linear
Ohms scale using a regular alkaline battery will make
the scales significantly inaccurate. I think the
drain is extremely low so I thought about designing
a voltage regulator circuit running off a higher voltage
battery but never got around to doing it.

The 600B is a nice meter. I picked mine up for $10 at
Dayton HF one year. Don't have a schematic though. If
you get a lead on that let me know.
Click to expand...
HF = hamfest??

Use a 1.5V alkaline button cell and recalibrate? Or else use 4.5V or
more battery and a micropower voltage regulator with a couple resistors
that give a 1.35V output. The current drain should be very low.


Dave Woolf - K8RSP
(If replying directly remove NOSPAM from above address)

George R. Gonzalez wrote:
HI, I have a clean-looking Keithley 600B electrometer.

Problem is, no manual, and no clue what kind of batteries it needs.

There's a small battery holder that maybe could hold a small
old-style
(1/3 AA) mercury battery. And FOUR clips that would fit your basic
9V
006P, except the holding bracket for them is about 8 times too
volume-iffic.

Any hints appreciated.

Reagards,

George
Click to expand...
 
"Watson A.Name - \"Watt Sun, the Dark Remover\"" wrote:
"Dave Woolf" <NOSPAMdwoolf@worldnet.att.net> wrote in message
news:413E65EC.9040907@worldnet.att.net...
George:

I also have a 600B. The four batteries are indeed 9V,
but a very early model. They are 1 3/8" x 1 3/8" x
x 2 5/8". I kept one just for the heck of it
that I removed from my original meter. It is a
zinc carbon EVEREADY no. 246. (NEDA 1602) Don't known
if still available, but I would guess if they are
you would pay an arm and leg for them. I use regular
size 9 V alk. batteries with reasonable battery life.

You guessed correctly the small cylindrical battery
is indeed a mercury cell (1.35 volts if I remember).
I kept it also but can't seem to locate it right now.
Good luck finding a replacement. I went looking for one
several years ago and found that it is illegal (Federal
Environmental Law) to sell or even import batteries
containing mercury. Never found a source. If you do
let me know. Since it is used for the linear
Ohms scale using a regular alkaline battery will make
the scales significantly inaccurate. I think the
drain is extremely low so I thought about designing
a voltage regulator circuit running off a higher voltage
battery but never got around to doing it.

The 600B is a nice meter. I picked mine up for $10 at
Dayton HF one year. Don't have a schematic though. If
you get a lead on that let me know.

HF = hamfest??

Use a 1.5V alkaline button cell and recalibrate? Or else use 4.5V or
more battery and a micropower voltage regulator with a couple resistors
that give a 1.35V output. The current drain should be very low.

Dave Woolf - K8RSP
(If replying directly remove NOSPAM from above address)

George R. Gonzalez wrote:
HI, I have a clean-looking Keithley 600B electrometer.

Problem is, no manual, and no clue what kind of batteries it needs.

There's a small battery holder that maybe could hold a small
old-style
(1/3 AA) mercury battery. And FOUR clips that would fit your basic
9V
006P, except the holding bracket for them is about 8 times too
volume-iffic.

Any hints appreciated.

Reagards,

George
Click to expand...
If one were to use one of those micropower regulators, one would need
to use a 1.25V adjustable and two resistors in a voltage divider...
 
"Winfield Hill" <Winfield_member@newsguy.com> wrote in message
news:ci7har02408@drn.newsguy.com...
Jim Adney wrote...

... If either of you want a copy just email me your address and
I'll Xerox one for you.

I also have replacement subminiature tubes for these, as well as
a circuit and method for matching them. I've resurrected several
of these, and their AC powered mates, over the years.

Thanks, I got the manual from Keithley's website. I have my
technician tear these apart for the teflon switches and Gig-ohm
resistors, but he did save some of the miniature tube assemblies.
Click to expand...
How does he remove them without getting his sweaty fingerprints all
over, and ruining the insulation properties? I'd guess he has to wear
gloves.

I used an open gate of a 2N7000 FET to probe for leakage. I found that
paper on a humid day works almost like the carbon element from a
potentiometer. I could probe from the negative to positive, and the
closer I got to the positive, the higher the FET current. It's kind of
amazing, when one thinks about it, but all this 'electron movement' is
going on between PCB tracks, and between wires in a bundle, etc. We
just don't kotice it because all the other much higher currents
overwhelm the leakages.

I was reading that they are having problems with the nanometer
geometries of the latest chip fabrications. The electrons get so leaky
that it's becoming a problem telling the signals from the leakage.

--
Thanks,
- Win

(email: use hill_at_rowland-dotties-org for now)
Click to expand...
 
Watson A.Name - \"Watt Sun, the Dark Remover\" wrote...
Winfield Hill wrote ...
Thanks, I got the manual from Keithley's website. I have my
technician tear these apart for the teflon switches and Gig-ohm
resistors, but he did save some of the miniature tube assemblies.

How does he remove them without getting his sweaty fingerprints
all over, and ruining the insulation properties? I'd guess he has
to wear gloves.
Click to expand...
I had him remove intact the amplifier assembly that contains the
tubes. But it's trivial to degrease items after handling them.

I used an open gate of a 2N7000 FET to probe for leakage. I found
that paper on a humid day works almost like the carbon element from
a potentiometer. I could probe from the negative to positive, and
the closer I got to the positive, the higher the FET current.
Click to expand...
Yes, paper, absolutely. Ever notice how much water it can absorb on
a humid day? It can get so wet you can't write on it with a pencil!

It's kind of amazing, when one thinks about it, but all this
'electron movement' is going on between PCB tracks, and between
wires in a bundle, etc. We just don't kotice it because all the
other much higher currents overwhelm the leakages.
Click to expand...
That's why I like extracting the teflon-terminal switches, etc., from
these old beauties. But even without them it's not too hard to make
fixed-range pA and fA sensitivity electronics, by using "in-the-air"
wiring, soldering items together suspended in air. For example, the
inverting input of a cmos opamp can be bent out from the rest, and
not put in a socket or soldered to the printed circuit board.


--
Thanks,
- Win

(email: use hill_at_rowland-dotties-org for now)
 
Achim Metzen wrote...
But I have not found Infos about any Battery for the 610B.
Click to expand...
I think a good answer is to replace the tube amplifier with a
cmos opamp, e.g. something from NSC's LMC6001 family. They
say the LMC662 has an input current of only 2fA typical. You
should add additioanl static protection, which can consist of
a pair of back-to-back JFET gate-source diodes.


--
Thanks,
- Win

(email: use hill_at_rowland-dotties-org for now)
 
Winfield Hill wrote...
Achim Metzen wrote...

But I have not found Infos about any Battery for the 610B.

I think a good answer is to replace the tube amplifier with a
cmos opamp, e.g. something from NSC's LMC6001 family. They
say the LMC662 has an input current of only 2fA typical. You
should add additional static protection, which can consist of
a pair of back-to-back JFET gate-source diodes.
Click to expand...
The LPC661 may be a better choice. It's an NSC single cmos opamp
with 2fA typical bias, but it works at a lower power level using
55uA from a 3 to 16V source, better suited for battery power.
http://www.national.com/pf/LP/LPC661.html The production part is
the LPC661IM, which is in an 8-pin soic package. NSC offers free
samples, or they're in stock for $1.98 each at DigiKey.


--
Thanks,
- Win

(email: use hill_at_rowland-dotties-org for now)
 
Winfield Hill <Winfield_member@newsguy.com>

[...]

I think a good answer is to replace the tube amplifier with a
cmos opamp, e.g. something from NSC's LMC6001 family. They
say the LMC662 has an input current of only 2fA typical. You
should add additional static protection, which can consist of
a pair of back-to-back JFET gate-source diodes.

The LPC661 may be a better choice. It's an NSC single cmos opamp
with 2fA typical bias, but it works at a lower power level using
55uA from a 3 to 16V source, better suited for battery power.
http://www.national.com/pf/LP/LPC661.html The production part is
the LPC661IM, which is in an 8-pin soic package. NSC offers free
samples, or they're in stock for $1.98 each at DigiKey.
Click to expand...

Win,

Do you have any recommendation for a low-leakage JFET? Wouldn't it
degrade the 2fA bias current? I understand from Paul Grohe's posts
that the bias current comes from the existing input protection
circuitry. Is there a good reason to add more protection?

Just for reference, here are some old links to these parts.

Paul Grohe talks about to obtain the low input current in

http://makeashorterlink.com/?B21513359

Bob Pease talks about testing and cleaning them them in

http://www.national.com/rap/Story/0,1562,4,00.html
http://www.national.com/rap/Story/0,1562,5,00.html

Paul discusses the source of leakage and how to clean them in

http://makeashorterlink.com/?N52521359

Thanks,

Mike
 
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