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12
4.1.2 Calibration of the combined humidity/temperature probe
Caution!
To calibrate the probes correctly, a knowledge of and abiding by the physical phenomena
on which the measurement is based is fundamental: this is the reason why it is recommended to
abide by what is reported below carefully and only to perform new calibrations if technically
proficient.
The probes are calibrated in our laboratory at 23°C at the points of 75%RH, 33%RH and 11.4%RH.
On request, the probes can be checked at different isotherms.
The calibration of the temperature sensor by the user is not required: the sensor is calibrated
in the factory and the Callendar Van Dusen parameters are recorded in the SICRAM module.
In order to calibrate the instrument correctly, it is very important for the probe and the
saturated solutions to maintain the same temperature and that this is as stable as possible
during the entire calibration operation.
Important: use saturated solution HD75, HD33 and HD11 with “R 2009” label.
Calibration sequence:
1.
Unscrew the sensor protection on the top of the probe.
2.
In its place screw the bored cap with the threaded ring very well at the base (there are two
types of thread: M24x1.5 and M12x1, so use the appropriate one).
3.
Open the cap for the 75%RH saturated solution.
4.
Should there be any drops of solution inside the measuring chamber, dry them with some
blotting paper.
5.
Insert the probe in the container, making sure the cap at the base is screwed well.
The
measuring chamber must be closed perfectly, otherwise it will not get saturated
: it is
essential that no air passes through it.
6.
Wait at least 30 minutes
.
7.
Press simultaneously the
DATA
and
UNIT keys
to open the menu;
8.
Press
DATA/ENTER
to reach the second menu item: the message
"PROB_CAL_EXIT_OR_75_OR_33_OR_11" is shown in the upper part of the display.
9.
To proceed with the calibration:
•
using the
and
arrows, select
75%
(placed respectively upper the HOLD and REL
keys;
•
confirm by pressing
DATA/ENTER
.
NOTE:
to exit without calibrating the probe, use the
and
arrows until the message
"nonE" appears in the central display and press
UNIT
.
•
the relative humidity read by the probe is shown;
•
if necessary, correct the value of the saturated solution against the 75.0% proposed by the
instrument using the arrows
and
.
The
temperature
is that measured by the Pt100 or TC sensor.
To confirm the calibration point
•
press
DATA/ENTER.
The instrument returns to the calibration main page and displays
"nonE".
To proceed with another point, select it using the arrows and confirm with UNIT.
Summary of Contents for HD2301.0R
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