Quest Engineering AQ5000 Pro, Инструкция по эксплуатации

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Chapter 3 Detailed Operating Instructions
17
Connecting and Calibrating Sensors
Before you begin displaying and recording data, you should
calibrate your CO
2
sensor to assure accurate readings. In addition,
using an optional toxic gas sensor and/or a linear output sensor
with the IAQ Monitor requires proper connection and calibration.
CO
2
, Temperature and Humidity Sensors
The CO
2
, temperature and humidity sensors are built into the wand
of the IAQ Monitor and cannot be removed.
The CO
2
sensor is an infrared sensor that requires air to be drawn
through it to produce a quick and accurate measurement of the
level of CO
2
in the air. The IAQ Monitor's built in sample pump
assures that air is drawn across the sensors. The CO
2
sensor
should be calibrated regularly to assure accurate readings.
The humidity sensor incorporates a capacitive sensor with a
monolithic CMOS circuit for a high reliability linear response. The
temperature sensor is a bead type thermistor with a fast response
to ambient temperatures. Both the temperature and humidity
sensors are calibrated at the factory and cannot be calibrated in the
field. We recommend you return the IAQ Monitor to Quest
Technologies for yearly calibration.
Calibrating the CO
2
Sensor
Calibrating the CO
2
sensor requires calibration gas, a regulator
(with a 1 liter per minute flow rate) and tubing.
We recommend using nitrogen (N
2
) gas for the zero calibration.
IMPORTANT: Care must be taken when choosing a span
calibration gas. The span calibration gas should be a sizable
fraction of the selected full scale range. If the span calibration is
performed using a low concentration span gas (i.e. 1,000 ppm), and
then the CO
2
sensor is exposed to a large concentration of CO
2
(i.e.
15,000 ppm), the CO
2
readings displayed may exceed the accuracy
specification.