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Liking Analog Meters Doesn't Make You a Luddite (Video)
Chris Gordon works for a high-technology company, but he likes analog meters better than digital readouts. In this video, he shows off a bank of old-fashioned meters that display data acquired from digital sources. He says he's no Luddite; that he just prefers getting his data in analog form -- which gets a little harder every year because hardly any new analog meters are being manufactured. (Alternate Video Link)
Especially when you don't need to know the exact number and you need a visual indicator that can be recognized at a glance.
Speedometers, tachometers, load balance reporting, etc...
I don't need to know the exact mbps that is currently getting pulled off my server, I need to know at a glance if my load is going into the red. I don't have the time to take my eyes off the road to read that I am traveling at 55.4 MPH @ 2571 RPMs, I just need to know that my needle is pointing up and left, and that my tach isn't pointing straight up.
That said, I want digital values for all of those things, streaming in real time through the appropriate systems, feeding logs, and populating data warehouses for later analysis.
-Rick
"Most people in the U.S. wouldn't know they live in a tyrannical state if it walked up and grabbed their junk." - MyFirs
Yeah, and although I weigh over 300lbs that doesn't mean I'm obese... because I say so...
There's plenty of analog meters being made every year. Just look at any automobile dashboard. They experimented with digital dashes back in the 80s and quickly abandoned them. Even Teslas, which have an LCD screen in the dashboard, have analog meters; they're just done in software, no different that a phone or PC that has an icon of an analog clock face.
Interestingly, though, modern cars with analog meters actually have them driven digitally; the indicator is really a servomotor, driven by digital information over a vehicle bus.
The reason analog instruments still prevail is because they can be interpreted easily at a glance (by looking at the position of the needle, rather than reading numerals and having to decide if those numbers are within a good range), and also because they show trends and rates of change which digital gauges do not.
I like analog meters because most digital meters suck. Digital meters sample, and most of them sample poorly. Good ones sample much faster than they update the display, and average per display update.
Analog meters, on the other hand, mechanically integrate and give some information about the frequency and range of a rapidly varying input. Additionally, they noticeably twitch better than many digital displays and give a much better awareness of rate of change than do digital gauges.
All of these problems are taken care of in good digital gauges. Not at all ironically, the good ones aggressively emulate analog gauges. The newer 747s I fly have tapes and gauges on glass that work very, very well. I have no complaints about them. Outside of aviation, though, the only digital gauges that don't suck are digital speedometers, and that's with a ton and a half of dampening.
Liking the command-line doesn't make someone a Luddite either.
It is very interested to watch trends in HMI design over many years, especially in the process industry.
In the 60s it was all about chart recorders. The exact pressure / temperature didn't matter, what was critical was a short term trend and operating roughly in the right place. They were easy to interprate and somehow entire refineries were run without fancy control systems.
Jump to the 80s and it was all about dotting numbers all over a screen in the name of progress.
At the turn of the century the numbers started getting longer. The worst case I saw was a differential pressure transmitter which displayed flow through a pipe in kg/h to 6 significant digits (yeah right).
In the last 5 years there's been a rise of what the industry is calling "High Performance HMI". And it's taking everything back to basics, back to what it was before some vendor gave people the option of plastering pretty graphics and numbers on a display. The move is now about removing all distractions, removing the colours, displaying short term graphing trends, limiting the numbers to only essentials and never more than 2 decimal places unless it's critical.
The inspiration of HpHMI is .... the airline industry. The A380 cockpit has 8 large LCD displays, yet what they display on them are analogue gauges.
Analogue gauges ignore the exact number in favour of quick and easy glances at current operating states. More importantly analogue gauges provide one thing that digital gauges never will, quick and easy rate of change information. Rather than calculating in your head you can simply see the needle move. It's an important bit of info that can't be shown any other way.
Take a look at any cockpit.
The autopilot heading: digital. The exact number is important. It doesn't change quickly. If it does change quickly then it's not important to know about it because likely something else is currently going wrong.
The altitude: analogue. The exact number is not important. Its rate of change is important.
We need to go thaw some designers from the 50s and 60s and put them back in charge to kill this obsession with numbers that seems to have crept in in the past 30 years.
There are two things that analog meters do very well that (most*) digital meters do either not at all or very badly.
One is rate of change. An analog meter in a wild overload condition will begin traveling very very fast, potentially giving you the opportunity to shut down before catastrophe occurs A digital meter will simply update its display a few times without any of the sense of urgency, and it's kaboom.
Another is getting a reasonable estimate from a dithering signal. A digital meter dithering between 100.2 Vdc and 99.8 Vdc will be almost unreadable if it updates too fast, and useless if it updates too slowly, but an analog needle hovering is an easy read. One can also mentally average "where the needle spends most of its time" much easier as well as seeing very short sharp drops.
And yes, I have an analog oscilloscope and a digital oscilloscope, and each have their advantages (I have lots of meters. I do electronics for a living).
AC
* - Fluke, and I suspect some more high-end brands, have a 'pseudo-analog' part of their display that does exactly what an analog meter does - Changes very fast, but not particularly precise. And it does work. AC
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he likes analog meters
I thought they were called "yards."
systemd is Roko's Basilisk.
Even Teslas, which have an LCD screen in the dashboard, have analog meters; they're just done in software, no different that a phone or PC that has an icon of an analog clock face.
That's not analog strictly speaking. That is a digital device imitating an analog display. Nothing wrong with that but it isn't the same thing. To be an analog device it has to operate on analog (continuous) signals. Digital devices by definition cannot do more than an approximation of a continuous signal. Possibly a very good approximation but an approximation nonetheless.
Interestingly, though, modern cars with analog meters actually have them driven digitally; the indicator is really a servomotor, driven by digital information over a vehicle bus.
If they are doing that then the meter isn't actually analog. Analog means something rather specific. If you run an analog signal through a A->D converter and then through a D->A converter you do not end up with the exact same signal you started with. It might be very useful to do that but you could accomplish the same end by simply using an analog device in the first place and not bothering with the conversions at all.
The reason analog instruments still prevail is because they can be interpreted easily at a glance
We use analog instruments to interpret analog signals because it is economical and sensible to do it that way. We can display the same information digitally in basically the same format if we desire to but in many cases this adds a lot of cost for little/no added benefit. It is simply often more cost effective to use analog devices to measure analog signals when practical. It's a keep-it-simple sort of philosophy. There is a time and a place for both digital and analog and that line can get pretty blurry sometimes.
It's receiving digital information, and using that to control a servomotor to position a needle, and looks a lot like old-time all-mechanical meters, but it's still analog in the sense that it's displaying information in an analog fashion, rather than as a numerical readout.
If it is receiving digital information then it is by definition a digital meter. What it physically looks like is irrelevant. That's like saying my iPod is analog because it's playing music in an analog fashion. It's not the same thing. If it isn't working directly with an analog signal it is NOT an analog device regardless of how old-timey it looks.
Digital! When arbitrary precision is mistaken for accuracy!
Mostly random stuff.
Liking Flash instead of supporting HTML5 video doesn't make you a Luddite.
Have gnu, will travel.