AH64ID

Why do you need an exact measurement at 873°? I can tell in an instant where my EGT's are accurately enough to know if I need to pay more attention. I can tell faster with analog, again I have both styles in my truck and have flown aircraft with both. Analog is faster/easier, providing a driver with more time to look at the road. Same thing with aircraft, our essential engine parameters are displayed in analog and digital. The analog is used to quickly glance at the conditions and then if you are near a limit you can look at the digital to see where it's at, but that takes more time and if your not near a limit there is no reason to know if your at 744° C or 80% of the way to a limit and one of those readings gets your eyes back outside faster.

I have a buddy with a Outlook, holy crap is EGT's are a pain to watch. The numbers are changing so fast all you really can read is the first digit or two, and you get zero reference to rate of acceleration like you do on a analog gauge.

annabelle

You may be able to read analog more quickly and I prefer digital......neither one of us has presented any scientific evidence as to which is processed by the brain more quickly, I'll just agree to disagree with you on this one.

annabelle

Well what research I have gleaned online says you are correct. Analog gauges are slightly quicker to read, but they are also less precise.

no_6_oh_no

Yes, they are more difficult to process and thats why the readings are backed up by visual and audio alarms. Same concept in air liners, the digital displays are backed by other alarms becuase it was found the lag to process could result in pilot error.

It really is not a fair comparison because the ratio of people able to fly a high end aircraft as opposed to drive a vehicle is so disparate. Failure to process speed fast enough in a vehicle geenrally ends up with a fender bender, failure to do the same thing in a high end aircraft frequently ends up making a crater in the ground.


No you don't and yes you do. You have trained yourself to apply that number to scale that is high and low and what is good. The number means nothing without context, its just a number. It still has to be applied to a scale. Additionally thta number has to be read the correct way and interpreted correctly to have meaning.

Example:

0015
5100
1500
5001
0051

The above all contain the same digits, they are the same length, etc. In order for the number to make sense you must read left to right as that is the way we interpet sequence. Even then it is still just a number with no reference, YOU must provide the reference and YOU have to decide what the reference is, temperature, psi, etc. With an all digital display you have many references and many disparate scales to apply the number to. That all MUST be done before the number makes sense.

You CANNOT know 1500 is a bad number UNLESS you read it correctly, apply it to a known scale, and interpret the position on the scale. That is a lot more steps than a needle position NOT where it normally is.

no_6_oh_no

Better do a little more research on that aspect. Digital gauges in these trucks have been shown to much less precise in their readings because they do no read source signal, only and interpreted signal from the ECU.

annabelle

EGT's, FP, tranny temp?

no_6_oh_no

Conversion from analog to digital always looses a little accuracy due to the interpolation algorithms used. The less you pay the wider the variance. Good accurate digital gauages are $$$$.

All the digitals seems to be slower to react and a smoother range. That is due to the shaping algorthms used for user experience. The ECU extensively modifies those readings to suit and expected result. Most of the digital processors do the same thing to one degree or another.

BroncoAZ

I have looked at these in the past, they look like a decent solution for me. If I were to add a Smarty Jr. I would want the safe start up mode.

I found it for $270 shipped with a free EGT pyro kit, seems like a great deal if it is a good unit. Looking at another thread on here the user didn't seem thrilled:

https://www.dieseltruckresource.com/...9&postcount=13

annabelle

What it the percentage of error of a analog gauge compared to that of a digital gauge?

no_6_oh_no

Directly dependent on the quality of the gauge which will be reflected in the cost. You can have a $180 or an $800 EGT gauge. Depends on how critical the measuring device needs to be.

An analog gauge it is setting the range based on the signal from the sensor. The gauge range is correlated to the sensor signal range.

With a digital the analog electrical signal is interpolated to a digital value. The number reading is correlated to the range of digital vlaues.

The interpolation introduces errors depending on the size and granularity of the conversion table. Size and granularity add memory and processing overhead which adds time to resolve. Its a tradeoff in cost, accuracy, and speed to generate an adequate user experience.

beewize

I still believe the benefits of a all in one digital/analog display with to many to list functions, that is easily installed, unplugged updated, repaired, moved, removed out weigh the permenant removal of the handy a-pillar handle, or install of 3or4 gauges somewhere. I hope the future trucks have these displays where the navi-sceen is. The new Long-Hauler has what looks like both analog and a sceen in middle of two gauges on the factory center stack, very nice.
It was interesting to learn about how my brain process info, i kind of thought i was into trucks because there wasnt much up there. AH-64 you have a awsome job, flying that is. Glad you have both types of gauges.

annabelle

Do any of the analog gauges have alarms as the digital gauges do, that inform you when you hit a predetermined value and actually bring your attention to a potential problem?(Allowing a driver more time to observe the road). Lets assume we are using a typical gauge package which is marketed by Autometer or the like for monitoring our trucks, not a high end specialized gauge that is not in most folks budget, when you calculate the percentage of error for an analog gauge. I am well aware that the more expensive an instrument is, the lower percentage of relative error for it's measurements.

cbx

AH64ID- I'm up in Kuna alot these days, several friends there and my father in law is there too. If you don't mind i'd sure like to take a ride in your truck after the Garrett turbo. I'm getting bored with my stocker and thinking about going all out.

As far as the guage thing goes, if anyone ever notices when driving analog anything, which from what i've been in, everything from john deeres, kenworths, dodges, and cessna 172's all share one thing. Safe zones of operation are almost always oriented at 12 O'clock position. You don't need The idea is just a sweep for Needles pointed up. all needles up straight, good to go.

stickler

We have the same issue in power stations. The engineers and geeky kids always want to have digital panel meters "because they're more accurate". Well, right at this minute I am in a control room containing 96 analog meters and 4 computer displays with digital readouts, and when the **** hits the fan, guess which ones are WAYYYYYY easier to deal with? Yup, the old analog, that your mind can register at a glance. The problem with digital is the numbers never stop changing long enough that you can recognize what they're saying. We don't CARE about exact numbers in those situations, what we need is a quick glance and be able to spot an abnormality, or sometimes just a direction of meter movement.