GrayWolf DirectSense - Performing Probe Calibration

20
Probe Calibration
The probe may be calibrated in one of three ways:
 at the factory, according to GrayWolf standards;
 at the factory (or an outside calibration laboratory) using NIST-certified
traceable standards;
 by the user (described in this section).
You cannot change factory and NIST calibrations.
Temperature is factory-calibrated. Dew Point
*
, which is
derived from Temperature and Relative Humidity, has no
calibration.
The three parameters you may change are Relative Humidity
(%RH)*, Carbon Monoxide(CO)* and Carbon Dioxide (CO
2
).
The range for each parameter has two pre-set calibration
points. Normally, you only change these points to match
reference gas or salt values for calibration.
Calibration should be performed at least every 12 months on
the %RH sensor and at least every 6 months on the CO and
CO
2
sensors. More frequent calibration is recommended if
the sensors are exposed to contaminants such as heavy
cigarette smoke. Note that most IAQ monitoring protocols
advise calibrating CO and CO
2
sensors more frequently.
The probe should be returned to the factory for temperature
calibration every 24 months. WolfSense provides kits for %RH,
CO and CO
2
calibration. See “Probes & Accessories” on page
31 for the contents of each kit.
To set up the correct calibration environment for Carbon
Monoxide(CO)* and Carbon Dioxide (CO
2
), place the flowhood
over the probe (Figure 35). For Relative Humidity (%RH)*,
place the probe upside down in the adapter on the jar of salt
solution (Figure 36).
*
DirectSense only.
Figure 35 - Calibration
Environment for CO or CO
2
:
Flowhood over probe
Figure 36 - Calibration
Environment for %RH:
Probe adapter on jar of salt
solution