How good are those Needle (Analog) Gauges?
Do
you
know the
truth about gauges- all needle gauges?
Automotive/
vehicle gauges. Most people understand that cheap gauges and gauge panels are
not very good. They just don't know why. But how are expensive gauges better?
Expensive
gauges use jeweled-bearing movements for the needles. This reduces stickiness
and improves accuracy. Try tapping the face of a cheap gauge; it will quite
often jump to a new reading. Expensive gauges also use more turns of finer
magnet wire in the movement's coil; which again improves accuracy. So far, so
good.
Once you buy that expensive gauge and have matched it to the proper
sender, do you know what size wire should be used to connect them? Plus, every
gauge is designed to be accurate at some exact vehicle voltage. What's your
rig's voltage? 12.0Volts, 13.2Volts, 14.6Volts? It depends on your battery,
fresh or tired, and who made it; toss in your alternator, its manufacturer and
output rating, engine RPMs of the moment, ambient temperature, and don't forget
the losses in your grounding system! Voltage variations alone are easily +15%,
causing a temp gauge measuring an actual 200 degrees F to read 170- 230 degrees.
How accurate are your expensive gauges? Not very! Plus the senders' values
change as the functions being measured change, and since all electric gauges are
really milliamp meters,
this guarantees that the most expensive gauge is never linear. Even if
"zero" and "full-scale" reads right, true
"half-scale" is never in the middle! Hope that the gauge's scale shows
that. Still want to rely on those gauges for you and your rig's safety?
How about a
gauge panel where every measurement is compared to a precision reference
voltage? Where the temperature sensors are voltage based and sensed by precision
amplifiers so they are absolutely linear? Where a constant-current generator
even drives the oil pressure sender so it's linear, too?
Where the wire lengths have no effect? Where the gauges include automatic
visual and audible alarms so when anything goes wrong, it alerts you, even if
you ignored them? Where also you can just glance at the gauge and know by the
color, just like a traffic light, if all's okay and you can proceed (green),
need to pay attention (yellow), or have a problem (red)-
STOP!? Just try ignoring the alarms!
Maybe you
should look at the high tech DIGI-PANEL.
It might just change the way you think about engine, transmission and driveline
monitoring.