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RH CALIBRATION
The HI 8064 thermohygrometer is factory cali-
brated, but it is recommended to periodically
control the calibration status of the meter.
Use the HI 7601 calibration kit composed of a
container with two separate chambers, each
one equipped with a threaded plug and three
envelops containing the necessary salts.
Preparing the calibration solutions
• Pour approximately 26 cc of distilled water
into a glass container.
• Immerse the container in a bath of ice and
water, and shake briefly. Then add slowly the
contents of an envelope containing LiCl to the
container while continuing to shake.
When the salt has completely dissolved, add
the contents of the second envelope.
• Allow the solution to cool, and then pour it into
the chamber marked "RH 11.1%", making
sure that no residue remains on the walls of
the glass container.
Note: When not in use, carefully seal the
chamber as the LiCl solution is ex-
tremely hygroscopic and tends to cap-
ture the air humidity causing the solution
to expand slowly until it overflows from
the container.
• Pour approximately 26 cc of distilled water
into the other chamber (marked "RH 75.4")
and add the contents of the envelope contain-
ing NaCl, while shaking the container to avoid
any lump formation.
Note: When not in use, carefully seal the
container.
SPECIFICATIONS
Range
10.0 to 95.0% RH
0.0 to 60.0°C
Resolution
0.1% RH / 0.1°C
Accuracy
±2% RH / ±0.4°C
Response Time
6 seconds for 95% accuracy
RH Calibration
Manual, 2 point, through
trimmers on the RH probe
Environment
0 to 50°C (32 to 122°F);
RH max 98% non-condensing
Battery Type
1 x 9V, alkaline
Battery Life
Approx. 100 hours of use
Dimensions
180 x 83 x 40 mm
(7.1 x 3.3 x 1.6'')
Weight
180 g (6.3 oz.)
• OFF position: the instrument is OFF; any
other knob position turn the instrument ON.
• ºC position: the meter is in temperature
measurement mode.
• RH% position: the meter is operating in
Relative Humidity measurement mode.
• Replacing battery: when the battery level is
low and only a few hours of working life are
left, the "V" symbol will appear on the
display to warn the user that the battery
needs to be replaced.
Remove the battery compartment rear cover
on the rear of the instrument and replace
the battery with a new one, while paying
attention to the correct polarity.
FUNCTIONAL DESCRIPTION