Yokogawa Single Channel Oxygen Analyzer System ZR22/ZR402 - Manual (Page 122)

IM 11M12A01-03E 8-10
In the example in Figure 8.4, the high-limit alarm point is set to 7.5%, the delayed time
is set to five seconds, and hysteresis is set to 2%.
Alarm output actions in this figure are expressed as follows:
(1) Although the measured value “A” has exceeded the high-limit alarm setpoint, “A”
falls lower than the high-limit alarm setpoint before the preset delayed time of five
seconds elapses. So, no alarm is issued.
(2) The measured value “B” exceeds the high-limit alarm setpoint and the delayed time
has elapsed during that measurement. So, an alarm results.
(3) Although the measured value “C” has fallen lower than the hysteresis set value, that
measurement exceeds the hysteresis set value before the preset delayed time has
elapsed. So, the alarm is not canceled.
(4) The measured value “D” has fallen below the hysteresis set value and the preset
delayed time during measurement has elapsed, so the alarm is canceled
8.3.3 Alarm Setting Procedure
To set the alarm setpoints, follow these steps:
(1) Press the Setup key in the basic panel display to display the Execution/Setup
display.
(2) Select Setup in the Execution/Setup display. The “Commissioning” (Setup)
display then appears.
(3) Select the Alarm setup in the “Commissioning” (Setup) display. The Alarms setup
display shown in Figure 8.5 then appears.
(4) Select Parameter in the Alarms setup display to display Oxygen, Humidity, and
Mixing, as Figure 8.6 shows.
(5) Select the Humidity and press the [Enter] key to confirm the humidity measure-
ment, as Figure 8.7 shows.
To set the hysteresis, proceed to the following steps:
(6) Select Hysteresis in the Alarms setup display. The numeric-data entry display
then appears. Enter the desired hysteresis value, in % H
2
O. To set 2.5% H
2
O, enter
“25.” The hysteresis can be in the setting range 0 to 9.9% H
2
O.
To set the delay time, proceed to the following steps:
(7) Select the Contact delay in the Alarms setup display. The numeric-data
entry display then appears. Enter the desired delay time, in seconds. To set three
seconds, enter “003.” The delay time setting can be in the ranges from 0 to 255
seconds.
To set the alarm point, proceed the following steps:
(8) Select Setpoints in the Alarms setup display to display the Humidity alarms as
shown in Figure 8.8.
(9) When you select “High alarm” in the display, the “off” or “on” selection display
then appears. If you select “on,” the High alarm will then be enabled(enable/
disable).
(10) To set the High alarm values, select the “Set value” just below the High alarm.
The numeric-data entry display then appears. Enter the alarm set value (in % H
2
O).
If you want to set the alarm value to 10% H
2
O, enter “0100.”
(11) Set the other alarm settings in the same manner as in the steps above.