On Wednesday, January 16, 2013 10:31:14 AM UTC-7, Dan Marotta wrote:
Maybe instrument design has changed, but I recall the counter, drum, pointer

altimeter needing a vibrator (read battery consumption) to keep the pointer

and digits from sticking. Or you could continuously tap the panel to keep

it moving...



"Bill D" wrote in message

...

On Tuesday, January 15, 2013 5:15:40 PM UTC-7, Craig R. wrote:

If I remember correctly, studies were done on the ability of the brain to

interpret and understand data quickly using either an analog or digital

readout. Time and speedometer readouts were the main emphasis of the

study. The study showed that the brain interprets the analog display

quicker and with greater accuracy. Besides the issue of running out of

power, it appears that the analog display is superior to digital for

information gathering and execution. Something to consider in going to an

all glass panel. Perhaps someone that is up on this subject could

elaborate?



That study was done very early in the digital age - 1960's IIRC. Current

studies show that while it remains easier to detect a trend with an analog

needle, a discrete value is easier to read in digits. Few would use an

altimeter to detect a trend so it works best as a numeric display which is

why few high performance aircraft use 3-hand altimeters anymore - in fact

they're pretty much relegated to gliders which means they're probably going

to disappear. Not many "little old Swiss watchmakers" left to fix them these

days.

Mine worked just fine without a vibrator.