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６．KINDS OF ALARM AND PERFORMANCE
６−１．Kinds of alarm
There are two kinds of alarms such as gas alarm and trouble alarm.
・Gas alarm：When detection gas reaches preset alarm level or exceeds it, this starts alarm.
《Latched mode→Self reset after reset operation.》
・Trouble alarm：Abnormal condition in this unit is detected and gives a trouble alarm.
Except system trouble 「E-00」, it is non-latched mode.
When return to normal from trouble condition, it starts again from the action of initial clear
after power on see section 「9. TREATMENT AT ABNORMAL CASE」.
６−２．Gas alarm
６−２−１．Gas alarm action
(1)Display
①Gas concentration
When exceeds detection range (Over scale), LED shows “∩∩∩∩”.
②Power light (Power：Green)
It keeps steady light.
③Alarm light （AL1：Orange）, （AL2：Red）
There are two alarm levels. When reading reaches each preset alarm level or exceeds each preset alarm,
level, this starts flashing and then returns to continuous lighting after reset operation, (Standard).
(2)External output
①4-20mA output
Electric current proportional to gas concentration. In case of over scale, the maximum output is 22mA.
②Alarm contact
When gas concentration reaches preset alarm level or it exceeds preset alarm level, relay contact is
activated.
Alarm relay contact is a latched mode. It returns self-reset mode when gas concentration decreases
below preset level after reset operation.
※ Alarm pattern is shown in the attached sheet.
＊ NOTE
Alarm levels are adjusted at 1/3 (1st alarm) and 2/3 (2nd alarm) of full scale.
To prevent wrong operation, this unit provides alarm delayed circuit for 2 seconds.
