Accuracy readings of a Fluke multimeter

J

Jim

Guest
Hi,


Can anyone explain the accuracy data of a multimeter specification.

I am looking at a Fluke 170 meter. The accuracy shown for the resistance is
+/- (0.9%+1) .

I understand the +/- bit, and I assume the percentage is a percentage of the
reading but what is the +1 about?

Any help appreciated.

Rgds


Jim
 
On a digital meter it is one count of the least significant
digit.

Jim wrote:
Hi,

Can anyone explain the accuracy data of a multimeter specification.

I am looking at a Fluke 170 meter. The accuracy shown for the resistance is
+/- (0.9%+1) .

I understand the +/- bit, and I assume the percentage is a percentage of the
reading but what is the +1 about?

Any help appreciated.

Rgds

Jim
Click to expand...
 
"Jim"(jim@SPAMTRAPprintedcircuitboards.net.invalid ) wrote:
I am looking at a Fluke 170 meter. The accuracy shown for the resistance is
+/- (0.9%+1) .

I understand the +/- bit, and I assume the percentage is a percentage of the
reading but what is the +1 about?

Any help appreciated.

Rgds


Jim
Click to expand...

Hi, Jim. The accuracy specification for digital meters is frequently listed as
+/- percent of reading +/- number of digits or counts. So, your specification
means that, on that range, the meter is accurate to /- 0.9% of reading +/- 1
digit or count.

(By the way, I think the spec on the Fluke 179 and other 170 series meters is
+/- 0.09% rather than 0.9%. This is a *very* good handheld meter, if a little
pricey, and just about indestructible under normal use. 0.9% accuracy is
something you'd expect from one of the generic sub-$30 knockoff meters.)

Let's say your spec is for DC Volts on a Fluke 179. So, if you read 10.00 VDC,
you are guaranteed accuracy of +/- 0.9% (+/- 0.09V) +/- 1 count (which would be
0.01V on that range). That would mean your maximum error would be +/- 0.10V.
In other words, the actual voltage could be anywhere between 9.9V and 10.1V.

If your Fluke 179 is rated for +/- 0.09% +/- 1 digit (the correct accuracy
specification), on a 10.00V reading your guaranteed error would be +/-0.09%
(0.01V) +/- 1 digit (0.01V), or +/- 0.02V. You're guaranteed that the actual
voltage is between 9.98V and 10.02V. Big difference.

Hope this has been of help.

Good luck
Chris
 
On 14 Jan 2004 21:04:46 GMT, cfoley1064@aol.com (CFoley1064) wrote:

"Jim"(jim@SPAMTRAPprintedcircuitboards.net.invalid ) wrote:
I am looking at a Fluke 170 meter. The accuracy shown for the resistance is
+/- (0.9%+1) .

I understand the +/- bit, and I assume the percentage is a percentage of the
reading but what is the +1 about?

Any help appreciated.

Rgds


Jim


Hi, Jim. The accuracy specification for digital meters is frequently listed as
+/- percent of reading +/- number of digits or counts. So, your specification
means that, on that range, the meter is accurate to /- 0.9% of reading +/- 1
digit or count.

(By the way, I think the spec on the Fluke 179 and other 170 series meters is
+/- 0.09% rather than 0.9%. This is a *very* good handheld meter, if a little
pricey, and just about indestructible under normal use. 0.9% accuracy is
something you'd expect from one of the generic sub-$30 knockoff meters.)

Let's say your spec is for DC Volts on a Fluke 179. So, if you read 10.00 VDC,
you are guaranteed accuracy of +/- 0.9% (+/- 0.09V) +/- 1 count (which would be
0.01V on that range). That would mean your maximum error would be +/- 0.10V.
In other words, the actual voltage could be anywhere between 9.9V and 10.1V.

If your Fluke 179 is rated for +/- 0.09% +/- 1 digit (the correct accuracy
specification), on a 10.00V reading your guaranteed error would be +/-0.09%
(0.01V) +/- 1 digit (0.01V), or +/- 0.02V. You're guaranteed that the actual
voltage is between 9.98V and 10.02V. Big difference.
---
Click to expand...
On the resistance ranges, it's either ą0.9% or ą 1.5% and either + 1,2,
or 3 counts (never negative) depending on range.

http://www.fluke.com/products/manuals.asp?SID=209&AGID=29

--
John Fields
 
On the resistance ranges, it's either ą0.9% or ą 1.5% and either + 1,2,
or 3 counts (never negative) depending on range.

http://www.fluke.com/products/manuals.asp?SID=209&AGID=29

--
John Fields
Click to expand...

Correct. Thanks.

Chris
 
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