Hach 8450, Инструкция по эксплуатации инструмента

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Section 3
Page 43
16116Operation.fm
Changing Site Location Designation
entered, the parameter for that menu can be changed, as can any other menu
parameter until the meter is resecured in the SEC menu.
When the correct password has been entered, the security must be manually
re-enabled (locked) in the “SEC” menu after all parameter changes are
complete, otherwise the meter will not be secured.
To change an existing password, enter the “change password” menu and
follow the message prompts.
3.20 Changing Site Location Designation
For purposes of identification, the site location may be changed from within
the “GEN” (general) menu. Up to 16 characters may be entered. To change
the site identification, enter the “GEN” menu and select the icon. The first
character will begin blinking. Use the arrow icons to scroll through the
available characters and numerals. After the desired character is selected,
select the
E
icon to store the character and move to the next character.
3.21 Changing Display Precision
The displayed decimal point precision of chlorine monitor’s output
concentration may be changed by entering the “RDG” menu and selecting
“Prec.” This menu allows placement of the decimal point at either 1.0, 0.1, or
0.01.
Figure 29 Display Precision Adjustment (Range Menu)
3.22 Damping Adjustment
The variability of the measured and displayed concentration value may be
controlled by adjusting the damping value. Low values of damping cause the
measured concentration value to respond rapidly to rapid changes in
concentration; higher values slow the response, thus “damping” out rapid
fluctuations in the readings.
Damping is useful for controlling variability of the concentration measurement
during calibration and also for controlling the stability of the display readout.
As a guideline when adding damping, an initial value of 5 seconds may
produce the desired stability. If necessary, this can be followed by an
additional 5 seconds and then 10-second intervals thereafter as needed (see
section 4.3 on page 54 ).
The value entered in the Damping menu establishes the duration of one time
constant. A time constant is a standard, nonlinear time vs. magnitude function
in which 63% of the maximum amplitude is reached in one time constant.
Additionally, two time constants reach 86%, three time constants reach 95%,
five time constants reach 99%, and an infinite number of time constants reach
100%. The concept of time constants versus percentage of maximum value is
depicted in
Figure 30 below. In this example, 20 seconds was entered for the
Damping value.
>Prec Damp
0.01 20