Resistance question

[AK]

I have read the manual for my Excel multimeter.

But it is not clear about resistance measurements.

I got 24.6 on the 200K scale. How do I convert that to ohms?

Thanks.

 

[AK]

On Saturday, May 4, 2019 at 7:15:30 PM UTC-5, AK wrote:

I have read the manual for my Excel multimeter.

But it is not clear about resistance measurements.

I got 24.6 on the 200K scale. How do I convert that to ohms?

Thanks.

If what I read is right, I would need to move the decimal to the right by 3 places.

So 24,600 ohms?

 

[Rheilly Phoull]

On 5/05/2019 8:54 am, AK wrote:

On Saturday, May 4, 2019 at 7:15:30 PM UTC-5, AK wrote:
I have read the manual for my Excel multimeter.

But it is not clear about resistance measurements.

I got 24.6 on the 200K scale. How do I convert that to ohms?

Thanks.

If what I read is right, I would need to move the decimal to the right by 3 places.

So 24,600 ohms?

Sounds good to me.

 

[Ralph Mowery]

In article <bd09a355-a82a-4ae7-81db-b91c4aa99547@googlegroups.com>,
scientist77017@gmail.com says...

ave read the manual for my Excel multimeter.

But it is not clear about resistance measurements.

I got 24.6 on the 200K scale. How do I convert that to ohms?

Thanks.

If what I read is right, I would need to move the decimal to the right by 3 places.

So 24,600 ohms?

Thats right. The K is for thousand (or 3 zeros) and if a M six zeros or
million. So you have 24.6 K or 24,600 ohms.

 

[John Larkin]

On Sat, 4 May 2019 17:54:33 -0700 (PDT), AK <scientist77017@gmail.com>
wrote:

On Saturday, May 4, 2019 at 7:15:30 PM UTC-5, AK wrote:
I have read the manual for my Excel multimeter.

But it is not clear about resistance measurements.

I got 24.6 on the 200K scale. How do I convert that to ohms?

Thanks.

If what I read is right, I would need to move the decimal to the right by 3 places.

So 24,600 ohms?

Probably. Does the selector knob, or something on the display, say
KOHMS?

Measure a few known resistors to figure out what that DVM does.

Good grief, $6.99 on ebay with free shipping from China.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[AK]

On Sunday, May 5, 2019 at 6:48:37 PM UTC-5, John Larkin wrote:

On Sat, 4 May 2019 17:54:33 -0700 (PDT), AK <scientist77017@gmail.com
wrote:

On Saturday, May 4, 2019 at 7:15:30 PM UTC-5, AK wrote:
I have read the manual for my Excel multimeter.

But it is not clear about resistance measurements.

I got 24.6 on the 200K scale. How do I convert that to ohms?

Thanks.

If what I read is right, I would need to move the decimal to the right by 3 places.

So 24,600 ohms?

Probably. Does the selector knob, or something on the display, say
KOHMS?

Measure a few known resistors to figure out what that DVM does.

Good grief, $6.99 on ebay with free shipping from China.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

Here is what my meter looks like.

"https://www.dropbox.com/s/9y9rpj4uooi71s0/Excel_Meter.png?dl=0"

 

[Adrian Caspersz]

On 06/05/2019 03:21, AK wrote:

John Larkin Highland Technology, Inc

lunatic fringe electronics

Here is what my meter looks like.

"https://www.dropbox.com/s/9y9rpj4uooi71s0/Excel_Meter.png?dl=0"

Do not use on line power.

--
Adrian C

 

[default]

On Sun, 05 May 2019 16:48:30 -0700, John Larkin
<jjlarkin@highlandtechnology.com> wrote:

On Sat, 4 May 2019 17:54:33 -0700 (PDT), AK <scientist77017@gmail.com
wrote:

On Saturday, May 4, 2019 at 7:15:30 PM UTC-5, AK wrote:
I have read the manual for my Excel multimeter.

But it is not clear about resistance measurements.

I got 24.6 on the 200K scale. How do I convert that to ohms?

Thanks.

If what I read is right, I would need to move the decimal to the right by 3 places.

So 24,600 ohms?

Probably. Does the selector knob, or something on the display, say
KOHMS?

Measure a few known resistors to figure out what that DVM does.

Good grief, $6.99 on ebay with free shipping from China.

I paid $2.95 at a local Harbor Freight store. Works as well as the
better ones and it is handy for the glove compartment and another I
keep as a back-up.

I expect Trump's tariffs will change that soon enough.

 

[AK]

On Monday, May 6, 2019 at 3:11:11 AM UTC-5, Adrian Caspersz wrote:

On 06/05/2019 03:21, AK wrote:


John Larkin Highland Technology, Inc

lunatic fringe electronics

Here is what my meter looks like.

"https://www.dropbox.com/s/9y9rpj4uooi71s0/Excel_Meter.png?dl=0"


Do not use on line power.

--
Adrian C

What is on line power?

 

[Adrian Caspersz]

On 06/05/2019 15:18, AK wrote:

What is on line power?

Sorry,

In the US, mains electric power is referred to by several names
including "household power", "household electricity", "house current",
"powerline", "domestic power", "wall power", "line power", "AC power",
"city power", "street power".

I call it Mains power over here, but I digress.

Really cheap unprotected meters can be somewhat explosive if
accidentally connected across the mains - especially with that 10A
unfused option.

Also given the cost, source, and look of the PCB, I'd not trust it.

https://lygte-info.dk/review/DMMXL830L%20UK.html

Perfect for low voltage projects though.

--
Adrian C

 

[AK]

On Monday, May 6, 2019 at 6:01:42 PM UTC-5, Adrian Caspersz wrote:

On 06/05/2019 15:18, AK wrote:

What is on line power?


Sorry,

In the US, mains electric power is referred to by several names
including "household power", "household electricity", "house current",
"powerline", "domestic power", "wall power", "line power", "AC power",
"city power", "street power".

I call it Mains power over here, but I digress.

Really cheap unprotected meters can be somewhat explosive if
accidentally connected across the mains - especially with that 10A
unfused option.

Also given the cost, source, and look of the PCB, I'd not trust it.

https://lygte-info.dk/review/DMMXL830L%20UK.html

Perfect for low voltage projects though.

--
Adrian C

Ok. So don't measure anything with the 10A, but the rest of the current ranges are ok?

I have use them before.

Andy

 

[Randy Day]

In article <3568c633-625c-4c8c-9e96-b55f33ceb6c4@googlegroups.com>,
scientist77017@gmail.com says...

[snip]

Perfect for low voltage projects though.

Ok. So don't measure anything with the 10A, but the rest of the
current ranges are ok?

I have use them before.

Andy

I think he means don't measure 120v/240v AC,
or other high, dangerous voltages. If you're
not experienced, those voltages can KILL.

The 10A current range can be OK, esp for
automotive, but you can get some good sparks
if you touch the wrong thing.

Not sure if this applies to you, but one
thing about low-cost multimeters; they
often come with a time limit (10 seconds)
for measuring current on the 10A range, so
take measurements quickly on that range.

HTH

 

[John Larkin]

On Tue, 7 May 2019 00:01:38 +0100, Adrian Caspersz
<email@here.invalid> wrote:

On 06/05/2019 15:18, AK wrote:

What is on line power?


Sorry,

In the US, mains electric power is referred to by several names
including "household power", "household electricity", "house current",
"powerline", "domestic power", "wall power", "line power", "AC power",
"city power", "street power".

I call it Mains power over here, but I digress.

Really cheap unprotected meters can be somewhat explosive if
accidentally connected across the mains - especially with that 10A
unfused option.

Also given the cost, source, and look of the PCB, I'd not trust it.

https://lygte-info.dk/review/DMMXL830L%20UK.html

Perfect for low voltage projects though.

The combination of the 600 volt ranges, the PC board, and the CE mark
is funny.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[AK]

On Monday, May 6, 2019 at 9:56:09 PM UTC-5, Randy Day wrote:

In article <3568c633-625c-4c8c-9e96-b55f33ceb6c4@googlegroups.com>,
scientist77017@gmail.com says...

[snip]

Perfect for low voltage projects though.

Ok. So don't measure anything with the 10A, but the rest of the
current ranges are ok?

I have use them before.

Andy

I think he means don't measure 120v/240v AC,
or other high, dangerous voltages. If you're
not experienced, those voltages can KILL.

The 10A current range can be OK, esp for
automotive, but you can get some good sparks
if you touch the wrong thing.

Not sure if this applies to you, but one
thing about low-cost multimeters; they
often come with a time limit (10 seconds)
for measuring current on the 10A range, so
take measurements quickly on that range.

HTH

Ok. I would never measure any AC current.

Just voltage.

Andy

 

[default]

On Tue, 7 May 2019 00:01:38 +0100, Adrian Caspersz
<email@here.invalid> wrote:

On 06/05/2019 15:18, AK wrote:

What is on line power?


Sorry,

In the US, mains electric power is referred to by several names
including "household power", "household electricity", "house current",
"powerline", "domestic power", "wall power", "line power", "AC power",
"city power", "street power".

I call it Mains power over here, but I digress.

We get it.

Really cheap unprotected meters can be somewhat explosive if
accidentally connected across the mains - especially with that 10A
unfused option.

The internal 10 shunt is usually a piece of heavy gauge wire. On a 20
amp circuit the circuit breaker goes before bad things happen. (as
one of our technicians proved time and again...)

There's a good reason for using honking big wire for the 10 amp range
in addition to making it hard to kill. They don't want too much heat
so the resistance of the shunt remains constant.

Also given the cost, source, and look of the PCB, I'd not trust it.

https://lygte-info.dk/review/DMMXL830L%20UK.html

Perfect for low voltage projects though.

I've got one that looks like his and it has proved good enough for me,
I do measure the mains voltage too. I had a nice expensive Fluke,
ruggedized case..., true RMS meter, with bells and whistles that
lasted until it dropped on the floor from about two feet.

Most of us learn to be careful. My lesson was as a kid (8-9 years old
- still used vacuum toobes, that's "valves" to you) I had this ~500 VA
plate transformer plugged in and measured the voltage 375 volts to the
center tap. Somehow I left it plugged in came back to it later and
was straightening out the leads and ran my fingers down across the
full 750 volts. I never made that mistake again. That was a sit-down
and shake experience.

In the navy I saw one of our techs working on a transmitter. He did
use the shorting bar (but it's ground wire was broken inside the
insulation) and the thing does have contactors that discharge the caps
when the covers are off. But none of that worked and he sent a spark
from his ass to the scope cart behind him.. He seemed fine right
afterwards, then he want into shock when he had time to think about
it.

I built telsa coils with 1,000 VA spark exciters and work with one
hand only and keep end of the power cord in my pocket... and
discharge the caps.

 

[John Larkin]

On Tue, 07 May 2019 10:10:40 -0400, default <default@defaulter.net>
wrote:

On Tue, 7 May 2019 00:01:38 +0100, Adrian Caspersz
email@here.invalid> wrote:

On 06/05/2019 15:18, AK wrote:

What is on line power?


Sorry,

In the US, mains electric power is referred to by several names
including "household power", "household electricity", "house current",
"powerline", "domestic power", "wall power", "line power", "AC power",
"city power", "street power".

I call it Mains power over here, but I digress.

We get it.

Really cheap unprotected meters can be somewhat explosive if
accidentally connected across the mains - especially with that 10A
unfused option.

The internal 10 shunt is usually a piece of heavy gauge wire. On a 20
amp circuit the circuit breaker goes before bad things happen. (as
one of our technicians proved time and again...)

There's a good reason for using honking big wire for the 10 amp range
in addition to making it hard to kill. They don't want too much heat
so the resistance of the shunt remains constant.

Also given the cost, source, and look of the PCB, I'd not trust it.

https://lygte-info.dk/review/DMMXL830L%20UK.html

Perfect for low voltage projects though.

I've got one that looks like his and it has proved good enough for me,
I do measure the mains voltage too. I had a nice expensive Fluke,
ruggedized case..., true RMS meter, with bells and whistles that
lasted until it dropped on the floor from about two feet.

The Extech DVMs are much higher quality, and most come with
thermocouple inputs, which is very handy for cooking and such.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[Cursitor Doom]

On Mon, 06 May 2019 20:09:22 -0700, John Larkin wrote:

The combination of the 600 volt ranges, the PC board, and the CE mark is
funny.

CE just means "Chinese Export" judging by the quality of some of those
things. Much better than they were 20 years ago, though. They've come on
in leaps and bounds. HOWEVER, when it comes to measuring anything mains-
related I would never use one. I've got a Megger for such occasions. The
equivalent in the US is Fluke. These two brands have *proper* protection
from high voltages at high energies. The cheap Chinese meters simply
aren't up to that sort of job.




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