3 oxygen concentration alarms setting, 1 setting the alarm values, 2 alarm output actions – Yokogawa Integral Oxygen Analyzer ZR202 User Manual

Page 112: Oxygen concentration alarms setting -6 8.3.1, Setting the alarm values -6, Alarm output actions -6

Advertising
background image

<8. Detailed Data Setting>

8-6

IM 11M12A01-02E

8.3

Oxygen Concentration Alarms Setting

The analyzer enables the setting of four alarms — high-high, high, low, and low-low alarms —

depending upon the oxygen concentration. The following section sets out the alarm operations

and setting procedures.

8.3.1

Setting the Alarm Values

(1) High-high and high alarm values
If high-high and high alarm values are set to ON, then alarms occur if measured valves exceed

the alarm set values. The oxygen alarm set values can be set in the range of 0 to 100 vol%O

2

.

(2) Low and low-low alarm values
If low-low and low alarm values are set, then alarms occur if measured values fall below the

alarm set values. The oxygen alarm set values can be set in the range of 0 to 100 vol%O

2

.

8.3.2

Alarm Output Actions

If the measured values of the oxygen concentration fluctuate between normal (steady state)

values and the alarm setting, alarm outputs may be frequently issued and canceled.

To avoid this, set the alarm delay and hysteresis for alarm canceling under the alarm output

conditions, as Figure 8.3 shows.

When a delay time is set, an alarm will not be issued so quickly even if the measured value differs

from the steady state and enters the alarm setpoint range.

If the measured value remains within the alarm setpoint range for a certain period of time (for the

preset delay time), an alarm will be issued. On the other hand, there will be a similar delay each

time the measured value returns to the steady state from the alarm setpoint range (canceling the

alarm status).

If hysteresis is set, alarms will be canceled when the measured value is less than or greater than

the preset hysteresis values.

If both the delay time and hysteresis are set, an alarm will be issued if the measured value is in

the alarm setpoint range and the delay time has elapsed.

For the alarm to be reset (canceled), the measured value must be beyond the preset hysteresis

value and the preset delay time must have elapsed.

Refer to Figure 8.3 for any further alarm output actions. The delayed time and hysteresis settings

are common to all alarm points.

Delay time:

5 seconds

7.5%

High limit alarm setpoint

5.5%

Oxygen concentration

Alarm output ON

OFF

Hysteresis

2.0%

A

B

C

D

Alarm range

Delay time:

5 seconds

Delay time:

5 seconds

F8.3E.ai

Figure 8.3 Alarm Output Action

8th Edition : Jan.13,2012-00

Advertising
This manual is related to the following products: