If you observe results that you don't understand and you want to verify that the ANKOMRF Gas Production System is functioning properly, run the RF Validation Test detailed in Service Procedure 124
Refer to the RF Curve Identification Chart in
Service Procedure 184 for curve illustrations.
The cumulative pressure in a module could decrease or go negative for the following reasons:
1) Communication errors between modules and the coordinator
- The module loses communications with the coordinator at the time of a valve vent cycle. When the module re-establishes communication, the actual pressure may be lower than what it was before the communication loss. This will be recorded as a cumulative pressure drop. The cumulative curve can be adjusted by adding an offset from the point of pressure loss. This offset is the difference between the pressure just before the communication loss and the pressure immediately following the communication loss.
2) Permeability through elastomeric components
- For robust performance, the ANKOMRF Gas Production System uses elastomeric components in the valve assembly. These components are slightly CO
2 permeable. In a pure CO
2 environment under 2 psi pressure, studies show that the permeability rate is approximately 0.02 psi/hr. As a result, this phenomenon can cause a slight loss of pressure that is evident at the end of the study when gas production is leveling off. This is a normal occurrence that can be corrected by running a blank in your study. See the
RF Getting Started Guide for more information.
3) Leak in the system
-A faulty seal between the electronics module and the bottle can cause the system to leak. Before running a study, inspect the rim of the bottle and remove any loose debris. Clean the gasket on the underside of the module, or replace if damaged. To ensure that the seal is good, attach the module to the bottle by screwing it on finger tight plus an additional 1/8 turn. Execute
Service Procedure 171 to test for leaks.
-To ensure that the vent valve is clean, see
Service Procedure 172.
-For bottles with Septa Ports, ensure that the septa connection is tight and the septum does not have holes.
4) Temperature change
-Pressure can change when temperature changes. For instance, if your modules are in an oven and the oven door opens, the pressure in the modules will decrease.
5) Absorption of CO
2 in the liquid
-In the beginning of a study, CO
2 can dissolve into the fluid until the fluid becomes CO
2 saturated. If CO
2 absorption happens faster than CO
2 production, then the net result will be negative
My module doesn't seem to be holding pressure. What should I do?