We used to use an LED stack for tank levels. Although it worked well some
customers did not like it, whereas most people seem to be happy with the
level gauge. The other problem with LEDs is that they are often difficult
to read in bright sunshine which is exactly what you often ( if you're
lucky ) get in an aircraft. The funny calibration is roughly eigth
intervals down the tank. It seems the Europa tank variation may in any case
exceed our best effort. With the system we use it is not possible to have
the switches very close together and therefor resolution is limited to not
much better than eight switches. In practice I would far rather have a
course resolution that worked than an infinite resolution that did not work
/ was inaccurate / or unreliable. I shall of course be using one of our
units in my own aircraft.
The manufacturer of one fuel level system said their unit could be worse
than 10% inaccurate depending on fuel used. I believe AVGAS gives more
consistant results than other fuels because the producers are tied to
tighter specifications. Unleaded is made up of a cocktail which meets the
specification on a given day. Winter time unleaded is quite different from
summer time unleaded.
In any case I shall be sending a unit to Jim soon. Let's see how it does.
I would be interested to know if anybody makes an LCD stack?
Jerry
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