Low and high tolerance

[ColinTheAmpMan1]

Hi,
It struck me recently that I have been misunderstanding these terms with respect to electronic components. I think of "high tolerance" as meaning that the component's actual value is very close to its stated value. So I think of a 0.1% resistor as high tolerance and a 10% one as low tolerance. Does anyone else see it this way?

My difficulty came when I realised that, for instance, if I didn't much like being kept awake by a neighbour's noisy party, I was displaying a low tolerance for the inconvenience. By my parallel with electronic components, this doesn't match up.

It doesn't seem right somehow to describe a close-tolerance as "low tolerance", but that is exactly what it is.

Maybe I have been labouring under a mistake for ages and have got it wrong. This wouldn't be the first time - I always thought that "gaol", as in "prison" was spelled and pronounced "goal" and only found out the truth a few years ago. Silly .

Colin.

[TonyDuell]

For components I prefer the terms 'close tolerance' (e.g. 0.1%) and 'wide tolerance' (e.g 20%). I've never used high or low tolerance relating to components, but to me 'large tolerance' would mean 'possibly inaccurate' e.g. 20%

[ColinTheAmpMan1]

Tony,
I agree with you that "close" and "wide" are better terms to use. I also agree that "large tolerance" pretty much means "possibly inaccurate".
Strangely, Horovitz and Hill are pretty uninformative on "low" and "high" tolerance....
Colin.

[kalee20]

I generally say 'precision' or 'close tolerance' for the accurate stuff and 'coarse tolerance' or 'wide tolerance' for the rest.

Not 'far' or 'distant' which are generally regarded as opposites of 'close.' Though 'fine' or 'narrow' which are opposites of 'coarse' and 'wide' would probably convey the intended meaning here.

[turretslug]

The same dichotomy occurs when using "under-rated" and "over-rated" with regard to component choice! I would talk about "under-rating" components for long term reliability (a 2N3055 to regulate the supply to a radio that uses a PP9 )- but I see and hear others talking about "over-rating" to achieve the same thing. It's a sort of are-you-looking-from-above-or-below kind of thing.

[wireless_john]

Originally Posted by TonyDuell

For components I prefer the terms 'close tolerance' (e.g. 0.1%) and 'wide tolerance' (e.g 20%). I've never used high or low tolerance relating to components, but to me 'large tolerance' would mean 'possibly inaccurate' e.g. 20%

I think that too!

[Phil G4SPZ]

It's easy to get confused by semantics, but perhaps best to think about tolerances in terms of 'margin for error'. If the component's value is critical for proper operation, then a close-tolerance (low likelihood of error) component should be chosen. Most good circuits are tolerant of variation in component values, within limits, due to good design.

I don't think that tolerances are talked about in terms of 'high' or 'low' in any branch of engineering. A tolerance is just that, +/- a specified dimension, quantity, value or percentage either side of a specified nominal value. 'High' and 'low' tend to be used to describe properties like stability and reliability, rather than tolerance.

[Andrew B]

Does that mean that low tolerance components are failed "high" tolerance components?

[TrevorG3VLF]

What about sub-standard?

[Malcolm G6ANZ]

I would say that an 'underrated' component is not up to the job it's required to do. EG using a 1W resistor where calculations show that a 5W one is needed. The converse would be overrating a component so the resistor in the previous example would be a 20W one.
I was told that a standard is a flag raised in battle to distinguish your side from the enemy. How does that work with the technical use of the 'standard' ?

Malcolm

[Phil G4SPZ]

Standard (with two completely different meanings) is just one example of English words that have at least two meanings, and sometimes many more. Indeed, it is difficult to think of a word that only has a single, unique meaning.

[trsomian]

High and low are much misused words in the English language, and, as pointed out by earlier contributors to this thread, frequently better replaced with something more descriptive. A good example of this is "high quality" and "low quality", which really are meaningless and should be replaced with "good quality" and "poor quality"

Phil's example of the word "standard" is also interesting, in that in the early years of the 20th century "standard" by implication was a good standard, hence the Standard Motor Company name implied a good standard of car, but by the 1960s standard had come to imply ordinary or basic, hence the name was dropped

[Phil G4SPZ]

I think the name "Standard" in the Motor Company was adopted from the military meaning of the word, as the Union Flag featured in Standard's motor car badge. They also named various models such as the "Vanguard" and "Ensign" in like manner. Good point, though, about "standard" coming to mean ordinary or basic, as in "standard class" rail travel. The Americans tend to use the word "regular" instead.

The use of "standard" to mean a fixed reference against which other are judged, e.g. The Gold Standard, the Standard Kilogramme etc, is completely different. Again, it just shows how efficient the English language has become, when the same word can have different meanings depending purely on the context. It also explains the popularity of the pun as a play on words!