TEL AFA4000/2, Инструкция по установке и эксплуатации

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AFA4000/2 Airflow Monitor / p.94
7.1.2 Calibration notes
•
For the Low Air sample open the sash to the max safe working height, when using a
Fume Cupboard with either Vertical Sliding or Horizontal Sliding sashes.
•
Make sure the sensor hose is connected correctly at the side wall and rear of the
sensor.
•
Make sure the extraction fan is running and the fume cupboard is balanced before
calibrating the monitor.
•
Take extra time, at least 15 to 20 seconds, to wait for the airflow to settle before
capturing the airflow samples. This will minimize the chance of a calibration error due
to turbulence or fluctuations.
•
Avoid movement in front of the fume cupboard whilst calibrating the monitor.
• The Low and High air samples must be at least 0.3 m/sec (60 fpm) apart to calibrate
the monitor. This is to avoid inaccuracy in the calibration due to insufficient difference
between the samples. The minimum difference can be changed in the Low High diff
parameter in the Cal Config menu.
•
The face velocity readings on the open sash may vary at different points on the
measuring grid by up to 0.1 m/sec. This is acceptable, long as individual points are
not below the designated Low Air alarm point.
•
The figure entered for the calibration point can be taken as the average value of all
the measuring grid readings or could be taken as the individual lowest point on the
grid. This low point is typically located in the centre of the bottom row. The low point
is a suitable convenient position to measure and for alarm testing.
•
When calibrating the alarm, it is important to ensure that the ‘Vent kit’ is connected to
the SM7 sensor on the fume cupboard. When the vent kit is not connected to the
sensor, the sensor will not detect a change in the airflow during the calibration
procedure and will display
Sensor Difference too low - Check sensor . This only applies
during calibration.
•
When the vent kit becomes disconnected following calibration the air flow across the
sensor will fall and the al
arm will go into the ‘Air Flow’ condition.
• When the airflow display is unstable as a result of environmental turbulence or sensor
position, following calibration, adjust the sensitivity of the displayed value using the