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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
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.
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.
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.