Beware Salter Electronic Kitchen Scales

On Sun, 25 Jan 2004 10:16:35 GMT, Farry
<[email hidden]> wrote:

| Hi.
|
| If anyone's considering buying one of those expensive Salter Electronic Kitchen Scales, you'll
| probably want to be aware of a design problem that messes up the accuracy. You can work around the
| problem, and still get accurate readings, but it is a rather daft fault. This is what I've put on
| Salter's feedback form, and I'm waiting for their reply:

I use the Salter electronic Aquatronic model number 3007, all plastic, and find it everything I had
hoped. I have checked the accuracy a few times and found it fine.

Dave F

Dave Fawthrop said:

I use the Salter electronic Aquatronic model number 3007, all plastic, and find it everything I had
hoped. I have checked the accuracy a few times and found it fine.

I would also have said that, but of the scale I bought a year ago, rather than the "compensated"
scale. When did you buy yours?

--
Farry

On Sun, 25 Jan 2004 10:38:41 GMT, Farry
<[email hidden]> wrote:

| Dave Fawthrop <[email hidden]> wrote:
|
| >I use the Salter electronic Aquatronic model number 3007, all plastic, and find it everything I
| >had hoped. I have checked the accuracy a few times and found it fine.
|
| I would also have said that, but of the scale I bought a year ago, rather than the "compensated"
| scale. When did you buy yours?

Sounds as if yours has a simple mechanical fault. Perhaps crud has built up inside, or the platform
has got twisted.

I have had mine about ?2? years.

I have just tried adding sugar slowly, no problem.

Dave F

Dave Fawthrop said:

On Sun, 25 Jan 2004 10:38:41 GMT, Farry <[email hidden]> wrote:

| Dave Fawthrop <[email hidden]> wrote:
|
| >I use the Salter electronic Aquatronic model number 3007, all plastic, and find it everything I
| >had hoped. I have checked the accuracy a few times and found it fine.
|
| I would also have said that, but of the scale I bought a year ago, rather than the "compensated"
| scale. When did you buy yours?

Sounds as if yours has a simple mechanical fault. Perhaps crud has built up inside, or the platform
has got twisted.

I have had mine about ?2? years.

I have just tried adding sugar slowly, no problem.

OK, the model 3007 is not displayed on their website, so I guess it's an old model and predates the
compensation trick.

As I said, it's the brand new scale that's got the problem. It's almost certainly designed into the
software because I can think of no way that a fault could introduce behaviour like that, but I can
think of why a software designer would want to add that compensation, if he didn't properly think
through the consequences.

--
Farry

On Sun, 25 Jan 2004 11:12:35 GMT, Farry
<[email hidden]> wrote:

| Dave Fawthrop <[email hidden]> wrote:
|
| >On Sun, 25 Jan 2004 10:38:41 GMT, Farry <[email hidden]> wrote:
| >
| >| Dave Fawthrop <[email hidden]> wrote:
| >|
| >| >I use the Salter electronic Aquatronic model number 3007, all plastic, and find it everything
| >| >I had hoped. I have checked the accuracy a few times and found it fine.
| >|
| >| I would also have said that, but of the scale I bought a year ago, rather than the
| >| "compensated" scale. When did you buy yours?
| >
| >Sounds as if yours has a simple mechanical fault. Perhaps crud has built up inside, or the
| >platform has got twisted.
| >
| >I have had mine about ?2? years.
| >
| >I have just tried adding sugar slowly, no problem.
|
| OK, the model 3007 is not displayed on their website, so I guess it's an old model and predates
| the compensation trick.
|
| As I said, it's the brand new scale that's got the problem. It's almost certainly designed into
| the software because I can think of no way that a fault could introduce behaviour like that, but I
| can think of why a software designer would want to add that compensation, if he didn't properly
| think through the consequences.

Just reread your original post.

As both an ex-engineer and a software writer, it still looks like a mechanical problem, and not a
software problem. My guess is that the platform is dragging, catching or juddering on something.
Mechanical problems sometimes build up slowly, or suddenly appear. Software problems are either
there, or not there, all the time.

Dave F

"Farry" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Dave Fawthrop said:

On Sun, 25 Jan 2004 10:38:41 GMT, Farry <[email hidden]> wrote:

| Dave Fawthrop <[email hidden]> wrote:
|
| >I use the Salter electronic Aquatronic model number 3007, all plastic,

and

Quoted message said:

Quoted message said:

| >find it everything I had hoped. I have checked the accuracy a few

times

Quoted message said:

Quoted message said:

| >and found it fine.
|
| I would also have said that, but of the scale I bought a year ago, rather than the
| "compensated" scale. When did you buy yours?

Sounds as if yours has a simple mechanical fault. Perhaps crud has built

up

Quoted message said:

Quoted message said:

inside, or the platform has got twisted.

I have had mine about ?2? years.

I have just tried adding sugar slowly, no problem.

OK, the model 3007 is not displayed on their website, so I guess it's an old model and predates
the compensation trick.

As I said, it's the brand new scale that's got the problem. It's almost certainly designed into
the software because I can think of no way that a fault could introduce behaviour like that, but I
can think of why a software designer would want to add that compensation, if he didn't properly
think through the consequences.

--
Farry

The kitchen scales use strain guages as the weight transducer. Although these are not linear in
output (which is compensated), they do not exhibit the fault you describe. Its more likely to be
a fault in the weighing platform suspension mechanism sticking (imagine a shaft going through a
hole and rubbing on the side). Probably a batch manufacturing problem. Check the batch number of
your model and take it back for exchange, making sure the new one is from a different
batch/manufacture date.

Dave

Dave Fawthrop said:

Just reread your original post.

As both an ex-engineer and a software writer, it still looks like a mechanical problem, and not a
software problem. My guess is that the platform is dragging, catching or juddering on something.
Mechanical problems sometimes build up slowly, or suddenly appear. Software problems are either
there, or not there, all the time.

OK, I've just done this.

1. Place clean mirror on worktop to make a perfectly flat surface.

2. Make sure both sides of scale are clean, and place on mirror.

3. Zero scale.

4. Put cereal bowl on scale - 274g.

5. Add tablespoon (20g) of muesli - 294g.

6. Tip out muesli and put bowl back - 274g.

7. Add same muesli back very slowly over 1 minute - 276g.
i.e. it's somehow lost 18g.

8. Tip out muesli and put bowl back - 256g. Still 18g down.

9. Remove bowl - and scale shows "----" (below zero).

This is quite repeatable. The scale is accurate and consistent, and does not drift even over several
minutes, PROVIDED that the weight changes are swift.

QED?

--
Farry

On Sun, 25 Jan 2004 13:08:45 GMT, Farry
<[email hidden]> wrote:

| Dave Fawthrop <[email hidden]> wrote:
|
| >Just reread your original post.
| >
| >As both an ex-engineer and a software writer, it still looks like a mechanical problem, and not a
| >software problem. My guess is that the platform is dragging, catching or juddering on something.
| >Mechanical problems sometimes build up slowly, or suddenly appear. Software problems are either
| >there, or not there, all the time.
|
| OK, I've just done this.
|
| 1. Place clean mirror on worktop to make a perfectly flat surface.
|
| 2. Make sure both sides of scale are clean, and place on mirror.
|
| 3. Zero scale.
|
| 4. Put cereal bowl on scale - 274g.
|
| 5. Add tablespoon (20g) of muesli - 294g.
|
| 6. Tip out muesli and put bowl back - 274g.
|
| 7. Add same muesli back very slowly over 1 minute - 276g.
| i.e. it's somehow lost 18g.
|
| 8. Tip out muesli and put bowl back - 256g. Still 18g down.
|
| 9. Remove bowl - and scale shows "----" (below zero).
|
| This is quite repeatable. The scale is accurate and consistent, and does not drift even over
| several minutes, PROVIDED that the weight changes are swift.
|
| QED?

Judder! A well known mechanical engineering problem. Often experianced in car brakes when the car
vibrates when braking. Friction varies with position and time, not like they teach you in school. I
have seen it in lots of things but never in scales.

Take it back and demonstrate the problem, Even a shop assistant should understand that it does not
work properly. Get a different model, it may be a batch problem.

Dave F

Farry said:

Quoted message said:

6. Tip out muesli and put bowl back - 274g.

7. Add same muesli back very slowly over 1 minute - 276g.
i.e. it's somehow lost 18g.

8. Tip out muesli and put bowl back - 256g. Still 18g down.

9. Remove bowl - and scale shows "----" (below zero). QED?

Interesting. Some recipes call for a half dozen ingreditents and I add them one a t a time. It can
easily take a few minutes as you put one away and get out the next. That would be a problem.

--
Ed [email hidden] pages.cthome.netedhomeOpen ↗

Dave Gibson said:

The kitchen scales use strain guages as the weight transducer. Although these are not linear in
output (which is compensated), they do not exhibit the fault you describe. Its more likely to be
a fault in the weighing platform suspension mechanism sticking (imagine a shaft going through a
hole and rubbing on the side). Probably a batch manufacturing problem. Check the batch number of
your model and take it back for exchange, making sure the new one is from a different
batch/manufacture date.

Unfortunately, there's no batch number, the model number is the same, and the appearance of the
old and new scales are identical, as far as I can remember. I believe that I've eliminated the
possibility of the mechanism sticking mechanically, so that leaves either a bizarre electronic
fault, or more likely in my opinion, an ill-thought attempt to compensate for drift in the
strain gauge.

--
Farry

Dave Fawthrop said:

Judder! A well known mechanical engineering problem. Often experianced in car brakes when the car
vibrates when braking. Friction varies with position and time, not like they teach you in school. I
have seen it in lots of things but never in scales.

Take it back and demonstrate the problem, Even a shop assistant should understand that it does not
work properly. Get a different model, it may be a batch problem.

I can't take it back to the shop, because I bought the original a year ago, and now I've just got a
replacement under guarantee by post from Salter. So I'll wait for the response from Salter to my
query, first.

I appreciate that it's hard to believe that this behaviour could be designed in. OK, next
experiment.

I repeat the process of adding muesli to the bowl three times, without zeroing the scale, and weigh
the bowl each time. It starts at 274g, then it's 254g, then 236g, then 216g. i.e. 18-20g down each
time leaving it 58g low. And since I completely remove the bowl from the scale to tip out the muesli
each time, that should have sorted out any judder.

--
Farry

Edwin Pawlowski said:

Interesting. Some recipes call for a half dozen ingreditents and I add them one a t a time. It can
easily take a few minutes as you put one away and get out the next. That would be a problem.

Actually, that can be a problem, but not for the reason that I've outlined. If you leave the scale
without changing the weight on it, the display will switch off after a couple of minutes to save
power, and you can't switch it on again without zeroing the scale. You have to remember to dab it
with your finger every minute to keep it alive, and the displayed weight will remain consistent.
Just don't pour in an ingredient too slowly.

--
Farry

On Sun, 25 Jan 2004 16:27:49 GMT, Farry
<[email hidden]> wrote:

| I can't take it back to the shop, because I bought the original a year ago, and now I've just got
| a replacement under guarantee by post from Salter. So I'll wait for the response from Salter to my
| query, first.

Salter offer a 10 year guarantee salterhousewares.comindex.aspOpen ↗
and click on 1004.

Why not get it swapped for a 3007 which they still sell on
salterhousewares.comindex.aspOpen ↗ Not as fancy but
it works OK.

Better than stripping what you have and risking buggering it up.

--
Dave Fawthrop <[email hidden]> Sick and tired of Junk Snail Mail? Register your family
surname and address with www.mpsonline.org.uk

Dave Fawthrop <[email hidden]> wrote in
:"]news:[email hidden]:

Quoted message said:

On Sun, 25 Jan 2004 13:08:45 GMT, Farry <[email hidden]> wrote:

| Dave Fawthrop <[email hidden]> wrote:
|
| >Just reread your original post.
| >
| >As both an ex-engineer and a software writer, it still looks like a mechanical problem, and not
| >a software problem. My guess is that the platform is dragging, catching or juddering on
| >something. Mechanical problems sometimes build up slowly, or suddenly appear. Software problems
| >are either there, or not there, all the time.
|
| OK, I've just done this.
|
| 1. Place clean mirror on worktop to make a perfectly flat surface.
|
| 2. Make sure both sides of scale are clean, and place on mirror.
|
| 3. Zero scale.
|
| 4. Put cereal bowl on scale - 274g.
|
| 5. Add tablespoon (20g) of muesli - 294g.
|
| 6. Tip out muesli and put bowl back - 274g.
|
| 7. Add same muesli back very slowly over 1 minute - 276g.
| i.e. it's somehow lost 18g.
|
| 8. Tip out muesli and put bowl back - 256g. Still 18g down.
|
| 9. Remove bowl - and scale shows "----" (below zero).
|
| This is quite repeatable. The scale is accurate and consistent, and does not drift even over
| several minutes, PROVIDED that the weight changes are swift.
|
| QED?

Judder! A well known mechanical engineering problem. Often experianced in car brakes when the car
vibrates when braking. Friction varies with position and time, not like they teach you in school.
I have seen it in lots of things but never in scales.

Take it back and demonstrate the problem, Even a shop assistant should understand that it does not
work properly. Get a different model, it may be a batch problem.

Dave F

Not convinced Dave. At least it must be coupled with a software fault if the bowl showed different
weights at different times.

--
Adrian

Farry <[email hidden]> wrote in
:"]news:[email hidden]:

Quoted message said:

Edwin Pawlowski said:

Interesting. Some recipes call for a half dozen ingreditents and I add them one a t a time. It can
easily take a few minutes as you put one away and get out the next. That would be a problem.

Actually, that can be a problem, but not for the reason that I've outlined. If you leave the scale
without changing the weight on it, the display will switch off after a couple of minutes to save
power, and you can't switch it on again without zeroing the scale. You have to remember to dab it
with your finger every minute to keep it alive, and the displayed weight will remain consistent.
Just don't pour in an ingredient too slowly.

So, what is the advantage of digital scales over my springy ones?

--
Adrian

Usually strain gaged loadcells have very small deflections. So movement sticking is unlikely to
be an issue.

Software issue may relate to low cost analog to digital conversion, reading frequency, etc.

"Dave Gibson" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

"Farry" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Dave Fawthrop said:

On Sun, 25 Jan 2004 10:38:41 GMT, Farry <[email hidden]> wrote:

| Dave Fawthrop <[email hidden]> wrote:
|
| >I use the Salter electronic Aquatronic model number 3007, all

plastic,

Quoted message said:

and

Quoted message said:

Quoted message said:

| >find it everything I had hoped. I have checked the accuracy a few

times

Quoted message said:

Quoted message said:

| >and found it fine.
|
| I would also have said that, but of the scale I bought a year ago, rather than the
| "compensated" scale. When did you buy yours?

Sounds as if yours has a simple mechanical fault. Perhaps crud has

built

Quoted message said:

up

Quoted message said:

Quoted message said:

inside, or the platform has got twisted.

I have had mine about ?2? years.

I have just tried adding sugar slowly, no problem.

OK, the model 3007 is not displayed on their website, so I guess it's an old model and predates
the compensation trick.

As I said, it's the brand new scale that's got the problem. It's almost certainly designed into
the software because I can think of no way that a fault could introduce behaviour like that, but
I can think of why a software designer would want to add that compensation, if he didn't
properly think through the consequences.

--
Farry

The kitchen scales use strain guages as the weight transducer. Although these are not linear in
output (which is compensated), they do not exhibit the fault you describe. Its more likely to be a
fault in the weighing platform suspension mechanism sticking (imagine a shaft going through a

hole

Quoted message said:

and rubbing on the side). Probably a batch manufacturing problem. Check

the

Quoted message said:

batch number of your model and take it back for exchange, making sure the new one is from a
different batch/manufacture date.

Dave

In message <[email hidden]>, Adrian Tupper <[email hidden]> writes

Quoted message said:

Farry <[email hidden]> wrote in
:"]news:[email hidden]:

Quoted message said:

Edwin Pawlowski said:

Interesting. Some recipes call for a half dozen ingreditents and I add them one a t a time. It
can easily take a few minutes as you put one away and get out the next. That would be a problem.

Actually, that can be a problem, but not for the reason that I've outlined. If you leave the
scale without changing the weight on it, the display will switch off after a couple of minutes to
save power, and you can't switch it on again without zeroing the scale. You have to remember to
dab it with your finger every minute to keep it alive, and the displayed weight will remain
consistent. Just don't pour in an ingredient too slowly.

So, what is the advantage of digital scales over my springy ones?

Well said. I have Dualit mechanical scales, which come up trumps all the time. The only problem is
that the bowl is large (not a problem) and round (a problem if you are tipping the contents into a
smaller bowl).
--
June Hughes

Quoted message said:

June Hughes

Quoted message said:

Fairy co.uk said:

"Edwin Pawlowski" wrote:

>Interesting. Some recipes call for a half dozen ingreditents and I add them one a t a time. It
>can easily take a few minutes as you put one away and get out the next. That would be a problem.

Actually, that can be a problem, but not for the reason that I've outlined. If you leave the
scale without changing the weight on it, the display will switch off after a couple of minutes
to save power, and you can't switch it on again without zeroing the scale. You have to remember
to dab it with your finger every minute to keep it alive, and the displayed weight will remain
consistent. Just don't pour in an ingredient too slowly.

So, what is the advantage of digital scales over my springy ones?

Well said. I have Dualit mechanical scales, which come up trumps all the time. The only problem is
that the bowl is large (not a problem) and round (a problem if you are tipping the contents into a
smaller bowl).

Yup, there has never been an instance where my analog springy scale hasn't sufficed. I can't think
of any occasion where I needed to cook by pharmaceutical-type measurements... like if you need to
measure your bread flour by the gram you really need to get the frig outta the kitchen.

---= BOYCOTT FRENCH--GERMAN (belgium) =--- ---= Move UNITED NATIONS To Paris =--- Sheldon
```````````` "Life would be devoid of all meaning were it without tribulation."

Quoted message said:

Quoted message said:

So, what is the advantage of digital scales over my springy ones?

--
Adrian

Greater accuracy.

Fred The Good Gourmet thegoodgourmet.comthegoodgourmet.comOpen ↗