Why do digital multimeters not have zero-blanking?

[floobydust]

Why do digital multimeters not have zero-blanking?
I was taught math, you added a leading zero if |ABS| less than one. Otherwise, no leading zeros.

I absolutely hate seeing multiple useless zeros displayed and realized it's confusing and dangerous- as Dave also commented i.e.  -0 989.3840 VDC on the Agilent/Keysight.
I expect the decimal point one digit to the right of the leading zero.

Observe this on all makes now. It better not be some cursed DIN standard on how to display a number.

I know Europe is different using comma verses decimal point in North America, and meters allow you to select the format.

[IanB]

It's because idiocy is contagious. It only takes one idiot to do it wrong and everyone thinks, "Oh, we should do that too!" -- and before you know it the wrong way has become the "right" way.

[Brumby]

I cannot see how they can justify it.  It is simply pointless and is more that you have to look at for no good reason.

In fact, I would call it a BAD move for the following reason:

When I see a leading zero, I look for a decimal point immediately to the right of it.  With this idiocy (good word, IanB) I now have multiple zeroes to examine -OR- I have to IGNORE it/them altogether if there is a non zero value to the left of the decimal.  It is a lot easier to ignore if it has already been blanked!

When you consider how much effort has been - and still is being - put into blanking out leading zeroes in computer displays and print outs, for the purpose of clarity in reading, then this move is simply indefensible.

If I had a bench meter - I would certainly not want to see such a display - and I would be turning everything upside down to find out how to restore proper blanking.

[Muttley Snickers]

I’ve never really been a fan of leading zeros and also find it a distraction on some meters, one thing I will say in its favour though particularly on older gear is at least it indicates that the area or segment of the display is working correctly and ready to tick over if required, probably more important on older LED, LCD and VFD displays.

[Brumby]

.... one thing I will say in its favour though particularly on older gear is at least it indicates that the area or segment of the display is working correctly and ready to tick over if required, probably more important on older LED and VFD displays.

I did consider that view - and while I can't say I've ever heard of a problem, I cannot dismiss this entirely.

However - for LCD displays and the like, it just isn't an argument.

[Muttley Snickers]

Sorry Brumby, you happened to have quoted my slightly earlier post which I replaced to include a reference to LCDs, referring to meters like the HP pictured below as opposed to that more modern stuff.   

[Ian.M]

Historic reasons:  Back in the days of dumb SSI and even discrete logic, leading zero blanking cost gates and thus money.   It was compounded by range switching that simply had an auxiliary contact to select one of the decimal points to feed power to to light it. The logic typically didn't even 'know' which d.p. was lit, so it would have required a lot of extra circuitry to blank all except the zero in front of the active d.p.

Newer meters after MCUs came into use in test equipment could have added leading zero blanking, but there was of course a tendency to retain the look & feel the customer base was already familliar and happy with.  Now its got over 60 years of tradition behind it, its unlikely to change  . . .

[Vtile]

It is actually only problem with autoranging unit. If it would be manual selection, you would know at which magnitude you are seeing on the display.

Atleast it gives a quick way to see if the number is in % or in PPM region of the scale.

[razberik]

What ? I never realized that !

I simply dont mind leading zeros. 

[capt bullshot]

Because doing otherwise (blanking leading zeros) would give you a false impression of the accuracy.
With all the leading zeros you can always see, if your DMM is switched to a reasonable range - if there are too many, you're using the wrong range.

I must admit, the HPAK Multimeter on your first pic (with the space separator between the first zero and the significant digits) does look wrong, and indeed - it is wrong: An "old style" DMM would suppress this first leading zero on the 1000V range, since they could only display a "1" or a "-" in the first digit, not a "0".

"Computerized" displays lead to all kinds of stupidity in terms of displaying measured values. Worst to see are the ones that treat everything as a float and display e.g. a room temperature reading with 5 digits after the decimal point - no joke, you can see such stupidity quite often in PC based software written by coders that do not know the usage of resolution and accuracy.

So, I'd always prefer a constant amount of displayed (or blanked but still kind of visible as seen in many modern multimeters having discrete LCD / LED displays) digits respresenting the actual resolution of the displayed value.

BTW.
Though beeing an European and beeing taught "," as the decimal separator, I do consider "." as _the only valid_ decimal seperator in science and technical issues, so any scientific or technical application displaying a "," gets cursed by me.

[Gyro]

Historic reasons:  Back in the days of dumb SSI and even discrete logic, leading zero blanking cost gates and thus money.

As an aside, some of the early discrete logic Datrons had NO leading zeros, a bit disconcerting. Luckily it could be fixed with a few track cuts and straps (no extra gates in this case). Even more disconcerting was their habit of completely blanking the display on overrange!

[StillTrying]

I absolutely hate seeing multiple useless zeros displayed

I hate them as well, I'd almost prefer a display flicking between 1 kHz and 1.008 kHz.

https://www.eevblog.com/forum/testgear/feeltech-fy6600-60mhz-2-ch-vco-function-arbitrary-waveform-signal-generator/msg1274555/#msg1274555

[Brumby]

History or not, it's not how I write numbers - so I would prefer to read them the same way.

As for blanking - I clearly remember layout out a numeric display PCB in 1975 using 7400 TTL - and routing the ripple blanking in and out....



Whatever the reasoning, I still don't like it.

[Benta]

I don't understand what you guys are on about.
My Fluke 179 blanks the leading zeroes, and IIRC, my previous multimeters did as well.

[madires]

I fully agree, displaying redundant leading zeros on non-vintage meters is ignorance. For example, some displays or fonts got tiny dots and a leading zero would help to indicate the dot. If multiple leading zeros are just for bragging, we'll see 3-1/2 digit DMMs with 8-1/2 displays soon

[bd139]

No excuse even on the vintage meters. It's not exactly as if ripple blanking isn't easy or common even going back 40 years!

[floobydust]

My ChemE university professor yelled at the class "not only are you engineering students illiterate, you are also innumerate!"

Basic Math and Pre-Algebra Workbook For Dummies:
"... when a 0 isn't to the right of any nonzero digit, it's a leading zero. Leading zero's are unnecessary and can be removed from a number."
The Chicago Guide to Writing about Numbers: the leading zeros are insignificant, they serve no purpose.

It's not historical -hardware supported ripple-blanking, even back in the 1970's when logic gates were precious. Example the ICL7135 4-1/2 digit A/D with SN7447 etc.

It seems to be a marketing thing. Wooo all those zeros, must be very accurate.

[Rolo]

I wondered about this also, long time my only meter was a Fluke. When a second meter came I noticed the leading zeros. It does not bother me much but supressing them does make the readout cleaner.

[Brumby]

Reminds me of an ancient episode of the Superman TV series with George Reeves.  An outcast alien from Mars, with the diminutive identity of Zero Zero Zero Minus One.


Sounds like he started it.

[electr_peter]

I would agree that multiple leading zeros are unnecessary and misleading. Nobody would say that "this car costs $15000 and it requires fuel at $00001 cost per litre". DMMs are designed by engineers - they should know about basic math rules and number representation.

Occasionally I would use extra leading zeros in case of alphanumerical sorting problems (so that "1 book", "10 books" would be changed to "0001 book", "0010 books"). Otherwise it is not very useful.

[schmitt trigger]

In the case of Keysight and Keithley, reputable and experienced equipment manufacturers over many, many years, the only reason I see is bragging rights: "look, how many digits I've got!"

[tooki]

I hate leading zeros. (In my "pimp my cheap lab PSU" project, I want to pad with spaces, i.e. decimal aligned. Sadly annoying to do with arduino.)

[Rbastler]

I guess marketing happend and the engineers/programmers, had to play along.

[Retep]

Some meters do blank the leading zeros, including the one on the left of the decimal point:

I do prefer the way Fluke handles the leading zero's however.

[tooki]

I guess marketing happend and the engineers/programmers, had to play along.

I doubt marketing had as much to do with it as some engineering decision early on. Once a company established a preference either way, they stuck with it.