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2.2 CONSTANT RATE Mode: Alarm Limits
SUMMARY:
This section allows the assignment of limiting values for several alarm conditions:
Cumulative Volume (CV)
(based on feed rate) in ml;
Lo-Flow
(LC)
(based upon collection rate
in ml/min;
Hi-Temp
(HT)
in
⁰
C;
Run Time (RT)
in Hours: Minutes;
Lo-Pressure (LP)
(monitor
system leakage) in psi;
Hi-Pressure (HP)
(filter back pressure) in psi;
Filtrate Weight (FQ)
in
grams.
Note: The alarm condition is triggered when the alarm limit is achieved.
Alarms are
not mutually exclusive. You may select any combination of alarms. For critical alarms (i.e. Lo-
Flow Alarm) you want the FilterTec Plus pump to stop (
Pump Stop
), for less critical alarm
conditions you may want to choose an auditory alarm (
Alarm Only
). Each alarm may be
disabled if not required.
Use
“Up”
and
“Down”
keys, then press
“Select”
to implement.
Cumulative Volume
(CV): This alarm setting represents the total volume of process solution
(based on the feed rate) that is delivered when a balance is not in use. Use the Filtrate Weight
Alarm for this purpose if you are using a balance! For example: if you set the Cumulative
Volume Alarm to 10,000ml or 10 liters, the FilterTec Plus will either alarm and/or stop the pump
when 10 liters of filtrate has been sent through the filtration device. Default = 1000.
Lo-Flow
(LC): At the end of the Constant Pressure portion of the process, this represents a
critical alarm condition. The FilterTec Plus will automatically decrease the pump rate to maintain
the selected Hi-Pressure Limit setting once the Pmaintain alarm has been triggered. The Lo-
Flow parameter (ml/min) represents lowest collection rate before the pump shuts down, and is
based on the collection rate (C1) when a balance is used and the Feed Rate (FF) without a
balance. Default = 0.
Hi-Temp
(HT): Used to monitor the temperature of the process solution, this will stop the pump
at the set limit. Default = 35.0
⁰
C
Run Time
(RT): This alarm setting allows you to set a timer for the filtration of your process
solution. For example, if you set the Run Time Alarm to 01:30, then the FilterTec Plus will
provide an auditory alarm and / or stop the pump after one (1) hour and thirty (30) minutes have
passed. Default = 01:00.
Lo-Pressure
(LP): Typically set 3-5 psi units below the Hi-Pressure setting. The Lo-Pressure
Alarm is triggered when a sudden filter backpressure drop occurs after rising above this setting.
Such a change in the filter backpressure usually indicates a significant system leak. This is a
critical alarm, set to Pump Stop. Default = 0.0.
Hi-Pressure
(HP): If you have chosen the Pmaintain in Alarm Enable, this is the value at which
the pump will change from the Constant Rate method to the Constant Pressure method. Setting
the Alarm to Pump Stop creates a Constant Rate only process that will stop when the Hi-
Pressure Limit is achieved. Default = 20.0 psi.
Filtrate Wgt.
(FQ): The FilterTec Plus comes with a top-loading balance. Enter the filtrate
weight (grams) that you want to collect, and the FilterTec Plus will either alarm or stop the
system when the desired weight has been collected. Set this value beyond the balance capacity
if you do not wish it to trigger during normal use. (If the balance goes negative at the start of the
run, the 0 gm default could trigger this alarm.)
NOTE: This alarm must be enabled to at least “Alarm Only” in order for the Q1 (Filtrate
Quantity) to be obtained or displayed. Default Limit = 0.