Vaisala AQT400, User Manual

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8. Maintenance
8.1. Overview to Maintenance
AQT400 has no moving or user-serviceable parts that require routine maintenance. Apart
from removing visible obstructions from the device.and adding new and calibrated gas
sensors every 12 ... 24 months, the air quality transmitters require no regular maintenance.
Opening the unit or breaking the security seal voids the warranty and the
calibration.
CAUTION!
8.2. Factory Calibration
To measure the four gases, AQT400 includes four integrated sensor elements. The sensors
have been calibrated at the factory and must be recalibrated every 12 ... 24 months,
depending on the gas type. To have the sensors replaced and calibrated, contact Vaisala
technical support.
8.3. Performance Check During
Operation
In addition to factory calibration, Vaisala recommends a regular performance check during
operation to ensure reliable measurements. The performance check verifies the
measurements and readjusts the measurement zero points with zero air. If possible,
complete the zero point calibration every 3 ... 6 months.
For more information on the performance check, see
A. Performance Check (page 39) .
Chapter 8 – Maintenance
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