Avionics News June 2020 - 26

Preston Pressure owner Kevin George works in the
background as his sons, Kyle George (left) and
Kent George, assemble a pitot-static tester.

PRESTON PRESSURE
Continued from page 25

the solution. They have nearly
indestructible sensors and longer
calibration periods, which reduces
the long-term costs and makes
them a wise investment choice.
"We've incorporated many
product improvements since our
original design, from improved
sensors and valves to displays
and software. We've provided
the software upgrades at no cost
or significant savings to our
customers."
In addition to its pitot-static
testers, Preston Pressure makes
an ALT-621 digital altimeter test
indicator and ASP-621 digital airspeed test indicator to replace
analog indicators in pitot-static testers.
"Made to the same form and fit as standard instruments,
they can be used to convert virtually any analog pitot-static
tester into a digital one," George said.
Seeing the digital trend
Nearly 25 years ago, while working as an avionics
technician at a repair station, George envisioned creating a
digital pitot-static tester.
"It occurred to me that the analog box that I was using
could be digital," George explained. "Since I knew
basic electronics, I figured it wouldn't take me long
to make a box. Little did I know that it would take
eight years of tinkering and learning before it would
become a reality. I had to learn more than I initially
realized, including PCB (printed circuit board)
and software design as well as microcontroller
operations and programming."
The hardest part of the early design
phase was finding a reliable
economical sensor that
retained an accuracy of
+/- 10 feet or better over
the operational temperature
range, according to George.
There were fewer sensor options
in the years 2000 to 2005 than there
are now.
Today, Preston Pressure's non-RVSM
testers typically register an error of +/- 7 feet or
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avionics news

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june

2020

less, which is much lower than some competitors' units.
"Their own spec sheets show +/- 30 feet, which is
worse than the old analog indicators," he explained. "By
comparison, the tolerance allowed for RVSM testers is just
+/-3 feet at sea level."
Once the design came together, George began to market his
new digital tester not knowing if it would sell.
"To my pleasant surprise, one sold almost immediately,
and we have been in business ever since then," George said.
"About a year ago, the first unit we sold in 2006 was returned
for upgrades and calibrations. Amazingly, it was still in use."
George sees several advantages to operating a family
business, including lower overhead
costs that keep unit prices
competitive. He hasn't raised
the price of the PS-525 since its
launch in 2006.
"My business practice has
always been to provide fast
and economical service to our
customers," George said. "Most
upgrades and minor repairs are done
at little or no cost. We also perform
annual calibrations of our own products
with typical turnaround times of two
days or less. It's another example of how
we're looking for ways to do more for our
customers." q

Preston Pressure's PS-525 digital pitot-static tester is
designed for small, non-RVSM aircraft.
Avionics News June 2020

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