Ametek Land 4200, Руководство пользователя

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User Guide Model 4200 Dust & Opacity Monitor
10.5.1 Preparation
The unit should be fully aligned and operational. Certain parameters as follows
should be set in preparation.
Select the Dust range by pressing the Mode key until the words 'OPAC' or 'duSt'
is displayed. Toggle the selection with F2 or F3 keys to select 'duSt'. Press F1
and hold key until display flashes on & off to save change.
Set the Dust Gain: Step through the selections using the Mode key until 'F' is
displayed in the right hand side of the display. Use F2 or F3 keys to set the Dust
Gain factor to 0.1. Press F1 key to save. (This value will need changing when the
isokinetic sampling results are known).
Set the Output Range to 200: Step through the selections using the Mode key
until 'r' is displayed in the left hand side of the display. Use F2 or F3 keys to
set the display value to 200. ( This gives a sensible range on the current loop
output during this test so that a chart recording can be used for averaging the
values). Press F1 and hold key until display flashes on & off to save change.
Select the Dust mode display: Step through the selections using the Mode key
until 'd' is displayed in the right hand side of the display. The display will now be
displaying the dust values in the stack.
10.5.2 Sample Readings
In order to calculate the Model 4200 for dust measurements it is necessary
to know the average dust value measured by the instrument during the period
of isokinetic sample. If several samples are taken, it is necessary to know the
average reading for each sample. It is possible to take readings directly from the
instrument's LED display a more satisfactory alternative is to use a chart recorder
or data acquisition system.
Note
The indicated dust value will not at this stage be an accurate measurement
of the amount of dust present since the Dust Gain has been set to an
arbitrary value.
10.5.3 Calculating the new Dust Gain Factor
When the samples have been analysed gravimetrically it will be possible to plot a
graph of isokinetic dust density against the Model 4200 dust value. Plot a 'best
fit' straight line passing through the origin and calculate the gradient of the line.
The Dust Gain can be calculated as Dust Gain factor = Gradient * 0.1
Where the value 0.1 is the original Dust Gain Factor.
See worked example, Fig. 10.3.