RKI Instruments Digester Gas Monitor - Manual (Page 45)

Digester Gas Monitor Operator’s Manual Battery Charging (Optional) • 39
3. After the minimum and maximum readings have been displayed for about ten
seconds, the following screen appears for about seven seconds.
• To reset the minimum and maximum readings, before the unit returns to Standby
Mode press and release the reset switch button. The display indicates Min/Max
Values Have Been Reset and the monitor will then return to Standby Mode.
• To return to Standby Mode without resetting the minimum and maximum readings,
do not press the reset switch button and allow the unit to return to Standby Mode.
Battery Charging (Optional)
The Digester Gas Monitor has an optional backup battery charging feature. In order for
this feature to be included, the Digester Gas Monitor must be ordered with this feature.
Consult RKI Instruments, Inc. for ordering information.
The battery charging circuit is designed to charge lead acid type batteries. If AC power is
used as primary power and a backup battery is connected to the Digester Gas Monitor‘s
EXT DC/24V BATT terminals as shown in Figure 14 on page 26, the battery charging
feature will charge the battery if it is depleted and keep it charged with a charge current of
approximately 100 mA.
CAUTION: When a battery is used as backup power and the charging feature is included
in the Digester Gas Monitor, do not use a non-rechargeable battery or a
backup battery that has its own charging feature. Use RKI backup battery
49-8104RK or an appropriately rated 24 VDC rechargeable lead acid type
battery to backup a Digester Gas Monitor when the battery charging feature
is included in the Digester Gas Monitor.
Alarm Indications
Gas alarms can occur at any point during the sampling period of the detection cycle. If the
gas presence was momentary and disappears quickly, the alarm indications will still be
active when alarms are set as latching (factory setting). In this case, the alarm indications
can be acknowledged and reset at any point during the detection cycle or while in Standby
Mode. If the gas was still present at the end of the sampling period, the alarm indications
can be acknowledged at any point but the alarm cannot be reset until the sampling period
of the next detection cycle.
This section describes the Digester Gas Monitor in alarm 1, alarm 2, alarm 3 and fail
conditions, and suggests responses to these conditions. Table 6 below lists the alarm
indications for each condition.
Push Reset Again To
Reset Min/Max Values
Or Wait To Return To
Normal Operation