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6.2.13 HD320B2 probe for the measurement of CO
HD320B2 probe measures the carbon dioxide concentration in air. It's indicated for checking and
monitoring the indoor air quality.
Typical applications are the check of the air quality in all the buildings where there is a crowd of
people (schools, hospitals, auditoria, canteens, etc.), in the working places to optimize the comfort.
CO
measurement is obtained with an infrared special sensor (NDIR technology: Non-Dispersive
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Infrared Technology) that, thanks to the use of a double filter and a special measurement technique,
warranties precise, stable and long-term measurements. The air to check is spread inside the
measurement chamber through the protection membrane placed at the top of the probe.
CO
probe calibration
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The probe is calibrated by the company and usually doesn't request any intervention by the user.
However, there is the possibility to execute a new calibration that corrects the sensor offset:
• at 400ppm in clean air
• at 0ppm with the help of nitrogen cylinder (code MINICAN.12A).
The instrument can automatically recognize the mode of the started calibration: if 400ppm or 0ppm.
The calibration has to be done on one point: each new calibration cancels the previous one.
The concentration of carbon dioxide in air is influenced by different factors: the human activities
(companies, pollution, combustion, etc.) cause an increase of this percentage in air. The calibration
value is equal to 400ppm and it's in clean air, for example in the country far from the more polluted
areas.
Go on as indicated below:
1. If you want to calibrate around 400ppm, make sure to apply clean air to the instrument
through a membrane placed on the head of the probe.
2. For the calibration at 0ppm, remove the cap placed at the base of the probe in order to
discover the plug of the calibration gas inlet and connect the tube coming from the nitrogen
cylinder. Adjust the fluxmeter of the cylinder on the flow from 0.3 to 0.5l/min.
3. Switch the instrument on and wait for at least 15 minutes before going on.
4. Press SHIFT FNC key: the shortcut window appears. With ▲▼ arrows select " cal CO2 "
and confirm with ENTER.
5. Supply CO
for at least 2 minutes in order that the measurement becomes stable.
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6. Going on supplying CO
which lasts three minutes , starts. In this phase the instrument measures CO
itself to a value next to 0ppm if you are using the nitrogen cylinder, at 400ppm if you are
calibrating it in clean air.
HD32.1
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to the probe, press F2 = CAL CO2 function key: the calibration,
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- 94 -
carbon dioxide concentration
and calibrates
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V2.1
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