The International
System of Units (SI), commonly known as the metric system, is the
international standard for measurement. The SI plays an essential role
in international commerce and is commonly used in scientific and
technological research and development. This cache is part of the
SI geoart that allows you to learn about the SI units.
Visit the introduction cache to
learn more about this geoart.
Electric current: ampere (A)
The ampere is the
SI base unit of electric current. An ampere is an electric current
equivalent to 1019 elementary charges moving every
1.602176634 seconds.
Historically, it is that constant current which, if maintained in two
straight parallel conductors of infinite length, of negligible circular
cross-section, and placed one metre apart in vacuum, would produce
between these conductors a force equal to 2×10−7 newtons per metre of length.

Electric charge: coulomb (C)
The coulomb is
the SI derived unit of electric charge. It is the charge transported by
a constant current of one ampere in one second.
The elementary charge, or the electric charge carried by a
single proton, is defined to be exactly
1.602176634×10−19 coulombs. Consequently, the coulomb is
equivalent to the charge of approximately 6.242×1018
protons.
Another subatomic particle, the electron, carries
negative one elementary charge. Therefore, -1 C is equivalent to the
charge of 6.242×1018 electrons.
This Geocache
One mole of electrons moved
through a boundary in 183432 ms. What’s the magnitude of the electric
current in amperes? Round it to an integer to get ABC.
Ampere balance is an electromechanical apparatus for the precise
measurement of the ampere. However, it has a major weakness that its
accuracy is limited by the measurement accuracy of its coils. B. P.
Kibble invented a successor that removes this source of inaccuracy. In
which year was the successor device invented? Divide this number by 5
and add 220 to get DEF.
Final coordinates: N 39° 08.ABC W 077° 08.DEF

You can validate your puzzle solution with
certitude.
Cache container is a baby-nano with tiny log sheet. A pair of tweezers
is mandatory for log retrieval. To conserve space, please omit the date
and write the first two letters of your username only.
Some hides are located along a road without sidewalk. For your safety,
please walk on the grass out of the car lanes, and avoid going at night
without wearing a safety vest.
Lists of Caches in SI geoart
-
introduction
-
second and hertz
-
metre
-
kilogram
-
m/s and km/h
-
mole
-
radian and steradian
-
m/s² and newton
-
m² and pascal
-
joule and watt
-
ampere and coulomb
-
volt and farad
-
ohm
-
kelvin
-
candela, lumen, and lux
-
bushel
-
foreword & afterword
-
prize distribution