Error of % + digits?...

[Ralph Mowery]

In article <op.0nw7h4ytwdg98l@glass>, CFKinsey@military.org.jp says...

I do have a Fluke test meter that is purty much fool proof up to 600
volts and rated CAT 4. A T1000. It only measuers AC amps by passing a
wire through the prongs. It does have a switch for voltage and ohms. I
have on purpose set it to ohms and put it across a fuse in a 480 volt AC
circuit to see if the fuse is good or bad. No problem to do this.

With a bad fuse it doesn\'t blow up?

No it does not . It is designed to protect its self from voltage on the
ohms scale. They are only about $ 130

Even better is a quick tester by Fluke. it has 2 leads and about 8 or
so leds on it. Both it and the T1000 look similar to bannanas, even
yellow in color. The 2nd tester is fully automatic. Connect the two
leads to anything under 600 or so volts. If voltage, the leds light up
, the more for more voltage. Anoter is for AC or DC. If there is less
than about 200 ohms and no voltage, there is a led and buzzer for that.

About as fool proof as they make it for quick tests.

 

[Ralph Mowery]

In article <op.0nw7h4ytwdg98l@glass>, CFKinsey@military.org.jp says...

I do have a Fluke test meter that is purty much fool proof up to 600
volts and rated CAT 4. A T1000. It only measuers AC amps by passing a
wire through the prongs. It does have a switch for voltage and ohms. I
have on purpose set it to ohms and put it across a fuse in a 480 volt AC
circuit to see if the fuse is good or bad. No problem to do this.

With a bad fuse it doesn\'t blow up?

No it does not . It is designed to protect its self from voltage on the
ohms scale. They are only about $ 130

Even better is a quick tester by Fluke. it has 2 leads and about 8 or
so leds on it. Both it and the T1000 look similar to bannanas, even
yellow in color. The 2nd tester is fully automatic. Connect the two
leads to anything under 600 or so volts. If voltage, the leds light up
, the more for more voltage. Anoter is for AC or DC. If there is less
than about 200 ohms and no voltage, there is a led and buzzer for that.

About as fool proof as they make it for quick tests.

 

[Ralph Mowery]

In article <op.0nw7h4ytwdg98l@glass>, CFKinsey@military.org.jp says...

I do have a Fluke test meter that is purty much fool proof up to 600
volts and rated CAT 4. A T1000. It only measuers AC amps by passing a
wire through the prongs. It does have a switch for voltage and ohms. I
have on purpose set it to ohms and put it across a fuse in a 480 volt AC
circuit to see if the fuse is good or bad. No problem to do this.

With a bad fuse it doesn\'t blow up?

No it does not . It is designed to protect its self from voltage on the
ohms scale. They are only about $ 130

Even better is a quick tester by Fluke. it has 2 leads and about 8 or
so leds on it. Both it and the T1000 look similar to bannanas, even
yellow in color. The 2nd tester is fully automatic. Connect the two
leads to anything under 600 or so volts. If voltage, the leds light up
, the more for more voltage. Anoter is for AC or DC. If there is less
than about 200 ohms and no voltage, there is a led and buzzer for that.

About as fool proof as they make it for quick tests.

 

[Commander Kinsey]

On Fri, 17 Jul 2020 23:37:07 +0100, Rich <rich@example.invalid> wrote:

In sci.electronics.equipment Commander Kinsey <CFKinsey@military.org.jp> wrote:
On Fri, 17 Jul 2020 21:26:15 +0100, Rich <rich@example.invalid> wrote:
As well, the user who\'d leave the leads plugged into amps, and then
try to measure voltage on car battery or other high current source
is also just as likely to leave the range switch in the amps setting
(after having measured current somewhere) and subsequently try to
measure voltage.

Nope. I pick up a multimeter and set it to what I\'m about to
measure. Same way as I don\'t drive into my house because I left my
car in forward gear yesterday.

Interesting....

Yet you said this yesterday:

From: \"Commander Kinsey\" <CFKinsey@military.org.jp
Date: Thu, 16 Jul 2020 20:09:20 +0100
Message-ID: <op.0nu3hup8wdg98l@glass

...

I find it crazy that you can select volts and have the wires in the
amps holes. ... I\'ve broken a meter doing that, just measuring the
voltage on a car battery. A £100 meter, but UNFUSED FFS!

...

One aspect of \"set it to what I\'m about to measure\" should normally
include: \"are the leads in the correct jacks\".

No, because it\'s illogical to change two things to set one thing.

 

[Commander Kinsey]

On Fri, 17 Jul 2020 23:37:07 +0100, Rich <rich@example.invalid> wrote:

In sci.electronics.equipment Commander Kinsey <CFKinsey@military.org.jp> wrote:
On Fri, 17 Jul 2020 21:26:15 +0100, Rich <rich@example.invalid> wrote:
As well, the user who\'d leave the leads plugged into amps, and then
try to measure voltage on car battery or other high current source
is also just as likely to leave the range switch in the amps setting
(after having measured current somewhere) and subsequently try to
measure voltage.

Nope. I pick up a multimeter and set it to what I\'m about to
measure. Same way as I don\'t drive into my house because I left my
car in forward gear yesterday.

Interesting....

Yet you said this yesterday:

From: \"Commander Kinsey\" <CFKinsey@military.org.jp
Date: Thu, 16 Jul 2020 20:09:20 +0100
Message-ID: <op.0nu3hup8wdg98l@glass

...

I find it crazy that you can select volts and have the wires in the
amps holes. ... I\'ve broken a meter doing that, just measuring the
voltage on a car battery. A £100 meter, but UNFUSED FFS!

...

One aspect of \"set it to what I\'m about to measure\" should normally
include: \"are the leads in the correct jacks\".

No, because it\'s illogical to change two things to set one thing.

 

[Commander Kinsey]

On Fri, 17 Jul 2020 23:37:07 +0100, Rich <rich@example.invalid> wrote:

In sci.electronics.equipment Commander Kinsey <CFKinsey@military.org.jp> wrote:
On Fri, 17 Jul 2020 21:26:15 +0100, Rich <rich@example.invalid> wrote:
As well, the user who\'d leave the leads plugged into amps, and then
try to measure voltage on car battery or other high current source
is also just as likely to leave the range switch in the amps setting
(after having measured current somewhere) and subsequently try to
measure voltage.

Nope. I pick up a multimeter and set it to what I\'m about to
measure. Same way as I don\'t drive into my house because I left my
car in forward gear yesterday.

Interesting....

Yet you said this yesterday:

From: \"Commander Kinsey\" <CFKinsey@military.org.jp
Date: Thu, 16 Jul 2020 20:09:20 +0100
Message-ID: <op.0nu3hup8wdg98l@glass

...

I find it crazy that you can select volts and have the wires in the
amps holes. ... I\'ve broken a meter doing that, just measuring the
voltage on a car battery. A £100 meter, but UNFUSED FFS!

...

One aspect of \"set it to what I\'m about to measure\" should normally
include: \"are the leads in the correct jacks\".

No, because it\'s illogical to change two things to set one thing.

 

[Commander Kinsey]

On Sat, 18 Jul 2020 00:10:49 +0100, Ralph Mowery <rmowery28146@earthlink.net> wrote:

In article <op.0nw7h4ytwdg98l@glass>, CFKinsey@military.org.jp says...
I do have a Fluke test meter that is purty much fool proof up to 600
volts and rated CAT 4. A T1000. It only measuers AC amps by passing a
wire through the prongs. It does have a switch for voltage and ohms. I
have on purpose set it to ohms and put it across a fuse in a 480 volt AC
circuit to see if the fuse is good or bad. No problem to do this.

With a bad fuse it doesn\'t blow up?



No it does not . It is designed to protect its self from voltage on the
ohms scale. They are only about $ 130

Howe does it measure ohms and distinguish its own current from the current from the circuit? That\'s if you\'re testing a DC circuit.

Even better is a quick tester by Fluke. it has 2 leads and about 8 or
so leds on it. Both it and the T1000 look similar to bannanas, even
yellow in color. The 2nd tester is fully automatic. Connect the two
leads to anything under 600 or so volts. If voltage, the leds light up
, the more for more voltage. Anoter is for AC or DC. If there is less
than about 200 ohms and no voltage, there is a led and buzzer for that.

About as fool proof as they make it for quick tests.

Does it check for current if there\'s no voltage?

 

[Commander Kinsey]

On Sat, 18 Jul 2020 00:10:49 +0100, Ralph Mowery <rmowery28146@earthlink.net> wrote:

In article <op.0nw7h4ytwdg98l@glass>, CFKinsey@military.org.jp says...
I do have a Fluke test meter that is purty much fool proof up to 600
volts and rated CAT 4. A T1000. It only measuers AC amps by passing a
wire through the prongs. It does have a switch for voltage and ohms. I
have on purpose set it to ohms and put it across a fuse in a 480 volt AC
circuit to see if the fuse is good or bad. No problem to do this.

With a bad fuse it doesn\'t blow up?



No it does not . It is designed to protect its self from voltage on the
ohms scale. They are only about $ 130

Howe does it measure ohms and distinguish its own current from the current from the circuit? That\'s if you\'re testing a DC circuit.

Even better is a quick tester by Fluke. it has 2 leads and about 8 or
so leds on it. Both it and the T1000 look similar to bannanas, even
yellow in color. The 2nd tester is fully automatic. Connect the two
leads to anything under 600 or so volts. If voltage, the leds light up
, the more for more voltage. Anoter is for AC or DC. If there is less
than about 200 ohms and no voltage, there is a led and buzzer for that.

About as fool proof as they make it for quick tests.

Does it check for current if there\'s no voltage?

 

[Commander Kinsey]

On Sat, 18 Jul 2020 00:10:49 +0100, Ralph Mowery <rmowery28146@earthlink.net> wrote:

In article <op.0nw7h4ytwdg98l@glass>, CFKinsey@military.org.jp says...
I do have a Fluke test meter that is purty much fool proof up to 600
volts and rated CAT 4. A T1000. It only measuers AC amps by passing a
wire through the prongs. It does have a switch for voltage and ohms. I
have on purpose set it to ohms and put it across a fuse in a 480 volt AC
circuit to see if the fuse is good or bad. No problem to do this.

With a bad fuse it doesn\'t blow up?



No it does not . It is designed to protect its self from voltage on the
ohms scale. They are only about $ 130

Howe does it measure ohms and distinguish its own current from the current from the circuit? That\'s if you\'re testing a DC circuit.

Even better is a quick tester by Fluke. it has 2 leads and about 8 or
so leds on it. Both it and the T1000 look similar to bannanas, even
yellow in color. The 2nd tester is fully automatic. Connect the two
leads to anything under 600 or so volts. If voltage, the leds light up
, the more for more voltage. Anoter is for AC or DC. If there is less
than about 200 ohms and no voltage, there is a led and buzzer for that.

About as fool proof as they make it for quick tests.

Does it check for current if there\'s no voltage?

 

[Ralph Mowery]

In article <op.0nw7h4ytwdg98l@glass>, CFKinsey@military.org.jp says...

I do have a Fluke test meter that is purty much fool proof up to 600
volts and rated CAT 4. A T1000. It only measuers AC amps by passing a
wire through the prongs. It does have a switch for voltage and ohms. I
have on purpose set it to ohms and put it across a fuse in a 480 volt AC
circuit to see if the fuse is good or bad. No problem to do this.

With a bad fuse it doesn\'t blow up?

No, it is designed to protect its self.

 

[Ralph Mowery]

In article <op.0nw7h4ytwdg98l@glass>, CFKinsey@military.org.jp says...

I do have a Fluke test meter that is purty much fool proof up to 600
volts and rated CAT 4. A T1000. It only measuers AC amps by passing a
wire through the prongs. It does have a switch for voltage and ohms. I
have on purpose set it to ohms and put it across a fuse in a 480 volt AC
circuit to see if the fuse is good or bad. No problem to do this.

With a bad fuse it doesn\'t blow up?

No, it is designed to protect its self.

 

[Ralph Mowery]

In article <op.0nw7h4ytwdg98l@glass>, CFKinsey@military.org.jp says...

I do have a Fluke test meter that is purty much fool proof up to 600
volts and rated CAT 4. A T1000. It only measuers AC amps by passing a
wire through the prongs. It does have a switch for voltage and ohms. I
have on purpose set it to ohms and put it across a fuse in a 480 volt AC
circuit to see if the fuse is good or bad. No problem to do this.

With a bad fuse it doesn\'t blow up?

No, it is designed to protect its self.

 

[Ralph Mowery]

In article <op.0nw9prwrwdg98l@glass>, CFKinsey@military.org.jp says...

About as fool proof as they make it for quick tests.

Does it check for current if there\'s no voltage?

Just how can there be curent if there is no voltage ?

There is no current by the leads, but works like a clamp on meter to
check for AC Current. Does not do DC current.

There can be voltage but no current.

 

[Ralph Mowery]

In article <op.0nw9prwrwdg98l@glass>, CFKinsey@military.org.jp says...

About as fool proof as they make it for quick tests.

Does it check for current if there\'s no voltage?

Just how can there be curent if there is no voltage ?

There is no current by the leads, but works like a clamp on meter to
check for AC Current. Does not do DC current.

There can be voltage but no current.

 

[Ralph Mowery]

In article <op.0nw9prwrwdg98l@glass>, CFKinsey@military.org.jp says...

About as fool proof as they make it for quick tests.

Does it check for current if there\'s no voltage?

Just how can there be curent if there is no voltage ?

There is no current by the leads, but works like a clamp on meter to
check for AC Current. Does not do DC current.

There can be voltage but no current.

 

[Cydrome Leader]

In sci.electronics.basics Commander Kinsey <CFKinsey@military.org.jp> wrote:

On Thu, 16 Jul 2020 08:30:20 +0100, Cydrome Leader <presence@mungepanix.com> wrote:

In sci.electronics.equipment Commander Kinsey <CFKinsey@military.org.jp> wrote:
On Sun, 12 Jul 2020 20:21:10 +0100, Tom Gardner <spamjunk@blueyonder.co.uk> wrote:

On 12/07/20 19:01, Pimpom wrote:
On 7/12/2020 11:15 PM, Commander Kinsey wrote:
On Fri, 26 Jun 2020 05:23:31 +0100, Cydrome Leader <presence@mungepanix.com
wrote:

In sci.electronics.equipment Pimpom <nobody@nowhere.com> wrote:

My mechanical slide caliper has a resolution of 0.001 inch. This
means that it can display measurements with a precision of 1 mil,

What if your caliper had a resolution of 1 mil +/- 3 counts on the last
digit?
.....<snip>........

In America, what is a \"mill\"? In the UK, it used to mean a thousandth of an
inch, but people use it to mean a millimetre nowadays.


It\'s not a mill. It\'s mil - single l. It means, and has always meant, a
thousandth of an inch. It\'s not an Americanism.

In the UK \"mill\" means millilitre.

If you want to refer to fractions of an inch, then
it is /always/ \"thou\", i.e. thousandths of an inch.

In the UK \"mil/mill\" /never/ means 0.001\".

Yes it does. My neighbour\'s a tradesman (in Scotland) and says
\"mill/mil\" (I don\'t know which as they sound the same in speech) as
shorthand for millimetre. As in \"that kitchen unit is 600 mill wide\".
Since we don\'t use inches for such things in the UK, there\'s no
confusion.

The context there is key too. While I\'d not measure a countertop or
whatever in millimeters, it would make no sense that anything in a kitchen
would be measured thicknesses of paper.

We (in the US) use \"guage\" for wire

Isn\'t that really hard to work out? We use cross sectional area in mm. Which is really easy to imagine. With the added bonus that a higher number is thicker. It\'s also pretty handy as a rough guide that 1 square mm carries 10 amps.

Not really. If you can only count with your fingers you probably aren\'t
building anything impressive to start with. The entire fallacy of \"metric
is easy, base 10, duh\" is just bullshit. Check dimensions of anything
designed by people that don\'t know what fractions are. There are tons of
weird numbers like 13.1mm and so forth. It\'s no different than 1-1/8th
inches.

and sheet metal.

Seriously? Wow. Why would you nbot measure a thickness in a unit of distance?

The guage for sheet metal is sort of obnoxious. It will vary by type of
metal as well, if that makes any sense.

We also use \"guage\"
for measuring really thin stuff like plastic films. In the last case, it\'s
a completly different unit, but with proper context won\'t confuse anybody.

We use microns.

how many microns thick is your plastic trash bag? The last ones I got were
speced on the box as \"0.7 mil\" There\'s no false sense of precision there,
like with the 610mm countertop or whatever it was.

Question for the metric woodworkers. Does anybody cut a piece of wood to
317mm or 429mm or other off numbers when building a house or handing a
door or installing a countertop?

Depends if something else is in the way. I\'d always try to use round numbers.

Would round be 320mm and 430mm instead of 317 and 429? Do you split in 5mm
increments too? I\'m really curious about this.

 

[Cydrome Leader]

In sci.electronics.basics Ralph Mowery <rmowery28146@earthlink.net> wrote:

In article <ret1h6$stk$1@dont-email.me>, rich@example.invalid says...

I suspect you would find changing the range switch while connected is
much more common than your response implies. Esp. for switching
up/down a range for meters that are not auto-ranging.

2) By having the amps jacks separate, the range switch itself does not
have to have contacts beefy enough to carry the current for the amps
settings. Remember, when measuring amps, the current being measured
flows *through* the meter itself. This would require very different
(and likely much more expensive) range switch contacts.

Or a relay.

Which also equates directly to added expense vs. having the user
themselves be that \"relay\". And for battery powered meters, shorter
battery life (due to the current consumed by the relay coil).

It is also possible (this is a guess in my part) that the CAT ratings
specify separate amps jacks for an added safety factor of \"user must
deliberately move lead to obtain short circuit through meter\".

As well, the user who\'d leave the leads plugged into amps, and then try
to measure voltage on car battery or other high current source is also
just as likely to leave the range switch in the amps setting (after
having measured current somewhere) and subsequently try to measure
voltage. It is not possible to fully protect users who don\'t pay
attention from doing stupid things. Either they forget to unplug from
the amps jack, or they forget to switch away from the amps range,
either way they get a local fireworks display of their own doing.




I often leave the leads connected to a Simpson 260 and change voltage
ranges. Where I worked there were so many wires in a conduit carrring
120 VAC control voltage it was difficult to tell if the voltage was
\'real\' or induced by the coupling. I found out that if I started on the
500 volt range and then switched to the 250 volt range if the meter
pointer stayed in the same relative position I could then switch to the
50 volt range and the meter pointer would still be near the same
relative position if the voltage was induced. If the pointer changed
positions to follow the 120 VAC when going to the 250 volt scale the
voltage was real.

The simpson meters are interesting in that they have as many jacks as they
they positions on the switch. You really need to move the leads around all
the time to do anything. I guest it makes you think, a little. I did catch
myself reading the ohms range wrong though recently.

I doubt that the CAT rating requies seperate Amps positions for the
leads. Fluke uses special fuses in their meters to get the CAT ratings.
They do not have a seperate jack for the ohms settings either which is
more likely where the meter would be set. Most of the time the
circuit would have to be broken and the meter inserted to measuer amps.

As you say it is impossiable to fully protect everyone from doing
somethen forgetful or stupid, but having a $ 300 meter instead of a $ 5
dollar one goes a long ways.

I do have a Fluke test meter that is purty much fool proof up to 600
volts and rated CAT 4. A T1000. It only measuers AC amps by passing a
wire through the prongs. It does have a switch for voltage and ohms. I
have on purpose set it to ohms and put it across a fuse in a 480 volt AC
circuit to see if the fuse is good or bad. No problem to do this.

I just got one of those clamp current multimeters. I noticed some glaring
limitations vs the full out Fluke 87 V, but at the same time, it\'s way
more \"idiot-proof\".

The current ranges, even for DC at only available though the current
clamp. It\'s just not possible to short anything out with the test probes.
The downside (not really surprising) is no low current ranges. Ok fine.
The input impedance is pretty low at 1Meg as well, but for poking at line
voltage wiring, this is fine. Again, no matter what range you are set it,
it appears to be impossible to blow up the meter as it has no low
resistance across the leads modes. The ohms range seems to max out at 40k
or something surprisibly low like that, again, no big deal for prodding at
lighting circuits or an outlet, or some 24 volt circuit.

Getting all sorts of wonky reading with the banana jack type K
thermocouple though. It seems the meter has an internal thermometer and it
compares to the junction at the end of the probe. Not really sure how that
all works and how the temperatures of the banana jacks affect things as
they are not the special metals in the leads of the probe. I know with
normal process controllers, and deviation of the correct connector or
metals used will result in really strange readings.

 

[Cydrome Leader]

In sci.electronics.basics Ralph Mowery <rmowery28146@earthlink.net> wrote:

In article <ret1h6$stk$1@dont-email.me>, rich@example.invalid says...

I suspect you would find changing the range switch while connected is
much more common than your response implies. Esp. for switching
up/down a range for meters that are not auto-ranging.

2) By having the amps jacks separate, the range switch itself does not
have to have contacts beefy enough to carry the current for the amps
settings. Remember, when measuring amps, the current being measured
flows *through* the meter itself. This would require very different
(and likely much more expensive) range switch contacts.

Or a relay.

Which also equates directly to added expense vs. having the user
themselves be that \"relay\". And for battery powered meters, shorter
battery life (due to the current consumed by the relay coil).

It is also possible (this is a guess in my part) that the CAT ratings
specify separate amps jacks for an added safety factor of \"user must
deliberately move lead to obtain short circuit through meter\".

As well, the user who\'d leave the leads plugged into amps, and then try
to measure voltage on car battery or other high current source is also
just as likely to leave the range switch in the amps setting (after
having measured current somewhere) and subsequently try to measure
voltage. It is not possible to fully protect users who don\'t pay
attention from doing stupid things. Either they forget to unplug from
the amps jack, or they forget to switch away from the amps range,
either way they get a local fireworks display of their own doing.




I often leave the leads connected to a Simpson 260 and change voltage
ranges. Where I worked there were so many wires in a conduit carrring
120 VAC control voltage it was difficult to tell if the voltage was
\'real\' or induced by the coupling. I found out that if I started on the
500 volt range and then switched to the 250 volt range if the meter
pointer stayed in the same relative position I could then switch to the
50 volt range and the meter pointer would still be near the same
relative position if the voltage was induced. If the pointer changed
positions to follow the 120 VAC when going to the 250 volt scale the
voltage was real.

The simpson meters are interesting in that they have as many jacks as they
they positions on the switch. You really need to move the leads around all
the time to do anything. I guest it makes you think, a little. I did catch
myself reading the ohms range wrong though recently.

I doubt that the CAT rating requies seperate Amps positions for the
leads. Fluke uses special fuses in their meters to get the CAT ratings.
They do not have a seperate jack for the ohms settings either which is
more likely where the meter would be set. Most of the time the
circuit would have to be broken and the meter inserted to measuer amps.

As you say it is impossiable to fully protect everyone from doing
somethen forgetful or stupid, but having a $ 300 meter instead of a $ 5
dollar one goes a long ways.

I do have a Fluke test meter that is purty much fool proof up to 600
volts and rated CAT 4. A T1000. It only measuers AC amps by passing a
wire through the prongs. It does have a switch for voltage and ohms. I
have on purpose set it to ohms and put it across a fuse in a 480 volt AC
circuit to see if the fuse is good or bad. No problem to do this.

I just got one of those clamp current multimeters. I noticed some glaring
limitations vs the full out Fluke 87 V, but at the same time, it\'s way
more \"idiot-proof\".

The current ranges, even for DC at only available though the current
clamp. It\'s just not possible to short anything out with the test probes.
The downside (not really surprising) is no low current ranges. Ok fine.
The input impedance is pretty low at 1Meg as well, but for poking at line
voltage wiring, this is fine. Again, no matter what range you are set it,
it appears to be impossible to blow up the meter as it has no low
resistance across the leads modes. The ohms range seems to max out at 40k
or something surprisibly low like that, again, no big deal for prodding at
lighting circuits or an outlet, or some 24 volt circuit.

Getting all sorts of wonky reading with the banana jack type K
thermocouple though. It seems the meter has an internal thermometer and it
compares to the junction at the end of the probe. Not really sure how that
all works and how the temperatures of the banana jacks affect things as
they are not the special metals in the leads of the probe. I know with
normal process controllers, and deviation of the correct connector or
metals used will result in really strange readings.

 

[Cydrome Leader]

In sci.electronics.basics Commander Kinsey <CFKinsey@military.org.jp> wrote:

On Thu, 16 Jul 2020 08:30:20 +0100, Cydrome Leader <presence@mungepanix.com> wrote:

In sci.electronics.equipment Commander Kinsey <CFKinsey@military.org.jp> wrote:
On Sun, 12 Jul 2020 20:21:10 +0100, Tom Gardner <spamjunk@blueyonder.co.uk> wrote:

On 12/07/20 19:01, Pimpom wrote:
On 7/12/2020 11:15 PM, Commander Kinsey wrote:
On Fri, 26 Jun 2020 05:23:31 +0100, Cydrome Leader <presence@mungepanix.com
wrote:

In sci.electronics.equipment Pimpom <nobody@nowhere.com> wrote:

My mechanical slide caliper has a resolution of 0.001 inch. This
means that it can display measurements with a precision of 1 mil,

What if your caliper had a resolution of 1 mil +/- 3 counts on the last
digit?
.....<snip>........

In America, what is a \"mill\"? In the UK, it used to mean a thousandth of an
inch, but people use it to mean a millimetre nowadays.


It\'s not a mill. It\'s mil - single l. It means, and has always meant, a
thousandth of an inch. It\'s not an Americanism.

In the UK \"mill\" means millilitre.

If you want to refer to fractions of an inch, then
it is /always/ \"thou\", i.e. thousandths of an inch.

In the UK \"mil/mill\" /never/ means 0.001\".

Yes it does. My neighbour\'s a tradesman (in Scotland) and says
\"mill/mil\" (I don\'t know which as they sound the same in speech) as
shorthand for millimetre. As in \"that kitchen unit is 600 mill wide\".
Since we don\'t use inches for such things in the UK, there\'s no
confusion.

The context there is key too. While I\'d not measure a countertop or
whatever in millimeters, it would make no sense that anything in a kitchen
would be measured thicknesses of paper.

We (in the US) use \"guage\" for wire

Isn\'t that really hard to work out? We use cross sectional area in mm. Which is really easy to imagine. With the added bonus that a higher number is thicker. It\'s also pretty handy as a rough guide that 1 square mm carries 10 amps.

Not really. If you can only count with your fingers you probably aren\'t
building anything impressive to start with. The entire fallacy of \"metric
is easy, base 10, duh\" is just bullshit. Check dimensions of anything
designed by people that don\'t know what fractions are. There are tons of
weird numbers like 13.1mm and so forth. It\'s no different than 1-1/8th
inches.

and sheet metal.

Seriously? Wow. Why would you nbot measure a thickness in a unit of distance?

The guage for sheet metal is sort of obnoxious. It will vary by type of
metal as well, if that makes any sense.

We also use \"guage\"
for measuring really thin stuff like plastic films. In the last case, it\'s
a completly different unit, but with proper context won\'t confuse anybody.

We use microns.

how many microns thick is your plastic trash bag? The last ones I got were
speced on the box as \"0.7 mil\" There\'s no false sense of precision there,
like with the 610mm countertop or whatever it was.

Question for the metric woodworkers. Does anybody cut a piece of wood to
317mm or 429mm or other off numbers when building a house or handing a
door or installing a countertop?

Depends if something else is in the way. I\'d always try to use round numbers.

Would round be 320mm and 430mm instead of 317 and 429? Do you split in 5mm
increments too? I\'m really curious about this.

 

[Cydrome Leader]

In sci.electronics.basics Ralph Mowery <rmowery28146@earthlink.net> wrote:

In article <op.0nw7h4ytwdg98l@glass>, CFKinsey@military.org.jp says...
I do have a Fluke test meter that is purty much fool proof up to 600
volts and rated CAT 4. A T1000. It only measuers AC amps by passing a
wire through the prongs. It does have a switch for voltage and ohms. I
have on purpose set it to ohms and put it across a fuse in a 480 volt AC
circuit to see if the fuse is good or bad. No problem to do this.

With a bad fuse it doesn\'t blow up?



No it does not . It is designed to protect its self from voltage on the
ohms scale. They are only about $ 130

Even better is a quick tester by Fluke. it has 2 leads and about 8 or
so leds on it. Both it and the T1000 look similar to bannanas, even
yellow in color. The 2nd tester is fully automatic. Connect the two
leads to anything under 600 or so volts. If voltage, the leds light up
, the more for more voltage. Anoter is for AC or DC. If there is less
than about 200 ohms and no voltage, there is a led and buzzer for that.

About as fool proof as they make it for quick tests.

Hmm, Remeber those neon voltage testers with two leads and the bizarre
shirt pocket clip? I had one go out on me, showed no voltage when there
was some. Whoops.

Now I use one of those ground/wiring testers. I figure it will still light
up if one neon indicator fails.