UK Cigar Scene Magazine September Issue 9 | Page 27

Habanos Specifications
Now Habanos SA, who should know something
about storing cigars has been putting an insert in
every box of cigars they ship since as long as I can
remember. It specifies a temperature of 16°C-18°C
and 65%-70% humidity.
Some things you CAN do.
Get one good cheap hygrometer, and check the
calibration @ about 68% RH when the weather
is fine, you’re not on a mountaintop, and the
room is about 20° C (68° F for you philistines).
If it is good, you are lucky.
If it is analog, you can adjust it.
If it is digital, and more than about 10% out,
turf it, or use it for something else.
Buy more cheap digital hygrometers, and test
them against your “standard”, in your actual
humidor, filled with actual cigars. Leave
enough time to stabilize-a couple of days
should be enough. From time-to time check
the readings on each hygrometer, and write
the differences down.
Put the “cheap” reading vs. “standard” reading
on a bit of tape and stick it to the “cheap”
meter.
IT’S GOOD ENOUGH. - Honest.
As long as you don’t let your humidor get more
that a few % from your “ideal”, it should be
accurate enough. Remember those % tolerances
above.

The ones we are interested in, using Sodium
Chloride, range from 75.51 +/- 0.34 % at 0 deg. to
76.29 +/- 0.65 % at 80 °C and leaves us working
with RH values as follows:
°C

°F

% RH

tolerance
(+/-)

15

59

75.61

0.18

20

68

75.47

0.14

25

77

75.29

0.12

Obviously hygrometers that read to the nearest
degree should be reading 75% RH if your room is
at normal “comfort” levels above 20° C (68° F). My
storage room temperatures are nominally 17-18° C
so I’m aiming at 76% since I have no instruments
that read 75.54 %.
The text that is included with the tables of values
call for a “slushy mixture with distilled water and
chemically pure salt”, so I would suggest noniodized (kosher or pickling) salt rather than table
salt.
The spec for the experiments that determined the
values mention a “sealed metal or glass chamber”
so an appropriately sized Tupperware should be
OK.
There was NO indication of how long it would take
for the calibration system to settle; I would guess it
will depend on the size of your chamber and type
of hygrometer.
I leave mine overnight.

On The Other Hand... You might want to Calibrate
your Hygrometer using the Famous “Salt Test”.
It is only really practical to calibrate hygrometers
at room temperatures since higher or lower temps
may cause mechanical changes in the instrument
that are too fussy to fool around with.
The Omega Engineering Temperature
Measurement Handbook lists all the types of salts
to use for various ranges of RH, from 9.9 at 100
°C using Lithium Chloride, to 98.77 at °C using
Potassium Sulphate.

An edited version of a document created by
Michael Barrett
© 2008-2009 Michael Barrett

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