Hach 54400-18, Инструкция по эксплуатации инструмента

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Page 38
Instrument Menu Structure
54400_start.fm
Section 2
Perform the procedure below to assign functions to AL1 or AL2:
1. Press the
MENU
key.
ALARMS
will be displayed.
2. Press
ENTER
to select
ALARMS
. The screen will display AL1 (or AL2),
and either the alarm set point (HI or LO), SA (System Alarm), or SW
(System Warning).
3. To change the AL1 (or AL2) assignment, press
ENTER
again. The item to
be changed will flash. The arrow icons indicate active arrow keys. Press
the
UP
or
DOWN ARROW
key to scroll through the available assignments.
Press the
RIGHT ARROW
key to change the value of the high or low alarm.
4. Press
ENTER
to select the displayed assignment.
5. Repeat the procedure to customize the other alarm relay.
In addition, a selection to recall or clear warnings is available. Access as
follows:
1. Press the
MENU
key.
ALARMS
will be displayed.
2. Press
ENTER
to select
ALARMS
. The resulting screen will display AL1 (or
AL2) along with the alarm set point (HI or LO), SA (System Alarm), or SW
(System Warning).
3. Press the
DOWN ARROW
key to scroll through the options.
4. When the appropriate option is displayed, press ENTER.
• RECALL WARNINGS —Momentarily shows all active warnings then
displays
DONE
.
• CLEAR WARNINGS —Clears all resolved warnings then momentarily
displays
OK
.
5. Press
EXIT
twice when done.
2.7.3 Setting the Recorder Output Span
This menu allows the Recorder Output High and Low limits to be set and also
offers the capability to use the ON SYSTEM ALARM option to communicate
an alarm condition. Use ON SYSTEM ALARM to send a signal to the control
room using the recorder output, to drive any device being controlled to full off,
or to maintain the present level if the analyzer goes into System Alarm status
and shuts off.
The CL17 is supplied with the recorder output set at maximum range. At
maximum range, a chlorine concentration of 0 mg/L provides an output of
4 mA and a concentration of 5 mg/L gives an output of 20 mA. The output
span can be adjusted to bracket any portion of the 0–5 mg/L range with the
4–20mA signal. For instance, this function can be used to bracket a lower
range for increased recorder resolution.
For example: if chlorine concentration of your sample is normally 0.5–0.7
mg/L, the recorder output span can be set for 0–1 mg/L (where 4 mA equals 0
mg/L and 20 mA equals 1 mg/L).