Delta OHM HD2301.0, Руководство по эксплуатации, Страница: 11 / 28

HD2301
- 11 -
V1.7
C
ALIBRATION 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.
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.
10. To return to measurement mode, use the

and

arrows until the message
"nonE" appears in the central display and press UNIT.
11. Remove the probe from the 75%RH container and close it immediately using its cap.