Keithley 2001 - do you need to open it to calibrate it?
I got the 2001 that I ordered yesterday. There are a few things that make
me feel uneasy about it, so I will probably return it.
The calibration seal is missing off the front, which is obvious from the
eBay photo, but also one at the bottom which looks as though one needs to
open in order to get inside the unit. That had a seal, but has been broken.
I'm wondering if that would be a normal part of the calibration routine, or
if someone has opened this up after it was calibrated.
The cal was due "Jan/12/10", which I assume means the 12th of January 2010.
Also, although when I see the pictures on eBay I never noticed it, a closer
inspection of the photos .
http://www.ebay.co.uk/itm/KEITHLEY-2001-DMM-/152113460174
does show that the hole on the front where a calibration seal would be
placed, has at one time in the past had a device too large pushed into the
hole. The hole is no longer round as I would expect it to be.
David,
I have found that many sellers like to remove any calibration stickers or
tamper evident stickers. Not sure why they do that as a sticker does not
mean the item is calibrated.
If you have 14 days, run it through the paces and perform self-tests. There
are some test scripts here https://xdevs.com/article/dmm_noise/ to see if
the meter is measuring close to others.
On Sun, Jun 26, 2016 at 3:12 PM, Dr. David Kirkby (Kirkby Microwave Ltd) <
drkirkby@kirkbymicrowave.co.uk> wrote:
I got the 2001 that I ordered yesterday. There are a few things that make
me feel uneasy about it, so I will probably return it.
The calibration seal is missing off the front, which is obvious from the
eBay photo, but also one at the bottom which looks as though one needs to
open in order to get inside the unit. That had a seal, but has been broken.
I'm wondering if that would be a normal part of the calibration routine, or
if someone has opened this up after it was calibrated.
The cal was due "Jan/12/10", which I assume means the 12th of January 2010.
Also, although when I see the pictures on eBay I never noticed it, a closer
inspection of the photos .
http://www.ebay.co.uk/itm/KEITHLEY-2001-DMM-/152113460174
does show that the hole on the front where a calibration seal would be
placed, has at one time in the past had a device too large pushed into the
hole. The hole is no longer round as I would expect it to be.
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On 26 June 2016 at 20:46, Todd Micallef tmicallef@gmail.com wrote:
David,
I have found that many sellers like to remove any calibration stickers or
tamper evident stickers. Not sure why they do that as a sticker does not
mean the item is calibrated.
The sticker on the front has been removed, but the one underdeath, which
covers a screw, is still there, but the screw has clearly been undone, so
the seal is "broken". I'm interested to know if it is necessary to undo the
case to calibrate the 2001, or whether it can all be done from the front
panel, probably removing that sticker on the front.
There are a few things I am not happy about this - the front panel appear
to move far more than I would expect. Depressing one key seems to make
several keys nearby go retreat towards the back of the unit, although it
appears to function.
I was a bit surprised when I put it on the 2 A range, with no leads
connected, the current is showing as high as 6 mA at times. This seems odd
given the current is obviously zero. I realize leaving the leads open on
voltage is going to lead to undefined results, but I would have expected on
current for the meter to read very close to zero.
If I put it on "auto", on DC current, with no leads, the reading is going
as high as 20 nA - there's noise on the last 3 digits. I don't know if that
makes any sense. The update rate is very fast, so perhaps that's to be
expected unless one increases the integration time.
But there are a few things making me think this meter might have issues. A
rather strange smell was initially evident, but that seems to have cleared.
The movement of the keys seems very odd. I will almost certainly return
this.
If you have 14 days, run it through the paces and perform self-tests. There
are some test scripts here https://xdevs.com/article/dmm_noise/ to see if
the meter is measuring close to others.
Thanks, I will take a look.
My computer that has the GPIB board in is is rather sick at the minute. I
need to sort out what is wrong with it, as its the only convenient computer
to have a controller card in.
Dave
You can run the self-tests to confirm the seller was telling the truth.
Smells are probably bad caps, and if you don't feel like dealing with a
recap, returning it would be best.
The keypad is held in place using two plastic strips. If one has broken or
fallen off, then you would see the keys push away from the panel. They are
easy to fix and are sometimes glued in place.
I am guessing it was opened and promptly put up for sale. I have repaired a
couple and they are great meters, but I am hesitant to go down that road
again. You never know how damaged they could be until you strip it down.
On Sun, Jun 26, 2016 at 5:29 PM, Dr. David Kirkby (Kirkby Microwave Ltd) <
drkirkby@kirkbymicrowave.co.uk> wrote:
On 26 June 2016 at 20:46, Todd Micallef tmicallef@gmail.com wrote:
David,
I have found that many sellers like to remove any calibration stickers or
tamper evident stickers. Not sure why they do that as a sticker does not
mean the item is calibrated.
The sticker on the front has been removed, but the one underdeath, which
covers a screw, is still there, but the screw has clearly been undone, so
the seal is "broken". I'm interested to know if it is necessary to undo the
case to calibrate the 2001, or whether it can all be done from the front
panel, probably removing that sticker on the front.
There are a few things I am not happy about this - the front panel appear
to move far more than I would expect. Depressing one key seems to make
several keys nearby go retreat towards the back of the unit, although it
appears to function.
I was a bit surprised when I put it on the 2 A range, with no leads
connected, the current is showing as high as 6 mA at times. This seems odd
given the current is obviously zero. I realize leaving the leads open on
voltage is going to lead to undefined results, but I would have expected on
current for the meter to read very close to zero.
If I put it on "auto", on DC current, with no leads, the reading is going
as high as 20 nA - there's noise on the last 3 digits. I don't know if that
makes any sense. The update rate is very fast, so perhaps that's to be
expected unless one increases the integration time.
But there are a few things making me think this meter might have issues. A
rather strange smell was initially evident, but that seems to have cleared.
The movement of the keys seems very odd. I will almost certainly return
this.
If you have 14 days, run it through the paces and perform self-tests.
There
are some test scripts here https://xdevs.com/article/dmm_noise/ to see
if
the meter is measuring close to others.
Thanks, I will take a look.
My computer that has the GPIB board in is is rather sick at the minute. I
need to sort out what is wrong with it, as its the only convenient computer
to have a controller card in.
Dave
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Hi All;
One thing to check for 0n the 2001 is leakage on the electrolytic caps. Especially the early ones (Identifiable by the finer mesh fan filter) commonly have this problem and if unattended the oil eats the traces making repair a real nightmare.
Cheers;
Thomas Knox
From: volt-nuts volt-nuts-bounces@febo.com on behalf of Dr. David Kirkby (Kirkby Microwave Ltd) drkirkby@kirkbymicrowave.co.uk
Sent: Sunday, June 26, 2016 3:29 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Keithley 2001 - do you need to open it to calibrate it?
On 26 June 2016 at 20:46, Todd Micallef tmicallef@gmail.com wrote:
David,
I have found that many sellers like to remove any calibration stickers or
tamper evident stickers. Not sure why they do that as a sticker does not
mean the item is calibrated.
The sticker on the front has been removed, but the one underdeath, which
covers a screw, is still there, but the screw has clearly been undone, so
the seal is "broken". I'm interested to know if it is necessary to undo the
case to calibrate the 2001, or whether it can all be done from the front
panel, probably removing that sticker on the front.
There are a few things I am not happy about this - the front panel appear
to move far more than I would expect. Depressing one key seems to make
several keys nearby go retreat towards the back of the unit, although it
appears to function.
I was a bit surprised when I put it on the 2 A range, with no leads
connected, the current is showing as high as 6 mA at times. This seems odd
given the current is obviously zero. I realize leaving the leads open on
voltage is going to lead to undefined results, but I would have expected on
current for the meter to read very close to zero.
If I put it on "auto", on DC current, with no leads, the reading is going
as high as 20 nA - there's noise on the last 3 digits. I don't know if that
makes any sense. The update rate is very fast, so perhaps that's to be
expected unless one increases the integration time.
But there are a few things making me think this meter might have issues. A
rather strange smell was initially evident, but that seems to have cleared.
The movement of the keys seems very odd. I will almost certainly return
this.
If you have 14 days, run it through the paces and perform self-tests. There
are some test scripts here https://xdevs.com/article/dmm_noise/ to see if
xDevs.com | DMM noise measurement test projecthttps://xdevs.com/article/dmm_noise/
xdevs.com
Test project of bench DMM noise levels evaluation, using DCV ranges and various NPLC settings.
the meter is measuring close to others.
Thanks, I will take a look.
My computer that has the GPIB board in is is rather sick at the minute. I
need to sort out what is wrong with it, as its the only convenient computer
to have a controller card in.
Dave
volt-nuts mailing list -- volt-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
and follow the instructions there.