by iteration69 » Sat Apr 16, 2011 6:13 am
Hydrogenworld,
Meyer's designs aside for the time being, you will need a cell design that can meet the strict requirements of scientific replication.
Take note that the scientific requirement of replication is traceable and pays particular attention to details. As you will see in the following rough draft outline.
First and foremost thee controlling variable in such a cell is the water. At first this may seem to be a trivial question but i assure you that this is not the case. A detailed log must be kept in regards to the water. Whether the water source be a natural spring, a well, city, deionized, distilled etc. Special care must be taken to use the same source in all experiments. If the source is changed then the log must reflect the change and continuing calibration verification (CCV) must be proven.
A quantifiable batch of water must be used, that is a large volume of water taken from a single source. The volume of water should be at least ten times your cell's capacity. Doing so will allow you to maximize the throughput of the apparatus while addressing initial quality control requirements(QC).
The standard operating procedure (SOP) requires standard conditions (ie, water quality) to be known and met prior to any experimental run. These conditions comprise of basic water tests:
-Water batch PH
-Water batch Specific conductivity
-Water batch total dissolved solids (TDS)
-Water batch total suspended solids (TSS)
Quantitative limits, both minimal and maximal must be determined and control mechanisms in place. That is, if a given batch of water is below or above some predefined limits, the batch must be rejected and the rejection cited in the log book.
Noting the source of the water, the time and date of the water sample, the batch size, the time and date of the experiment, the water analysis results, the technician's signature, and the documented SOP in a log book, the experiment is now permitted to continue in a documented, traceable manor.
Now that we have a given batch of water that has passed basic QC requirements we can move on to determine the thermal capacity of the apparatus. In order to cite thermometric figures relative to the apparatus, another set of standard conditions must be defined, met, and documented.
We will call this "thermal base line". The thermal base line itself has it's own set of strict rules which must be met.
1) The apparatus may not be changed in any way during experiments
2) A calibrated volume of water must be used during all experiments
3) A calibrated thermal source must be used to raise the temperature of the apparatus by a predefined stimulus unit. Note that this unit is not required to be reported as a thermal unit, it may be ohms, voltage, or current. But it must be repeatable.
A few notes on the thermal base line requirements. It's easy enough to ensure the cell does not change during test, simply and strait forward - do not touch it in any way. In order to ensure that a calibrated volume of water is delivered to the cell an intermediate stage must be constructed. This intermediate stage will also require replication to be proven, to do so, we use digital balance that has been proven to be repeatable given our mass-range of water. The time and date, the mass and stimulus unit, and the technicians name will be cited in the log book. The thermal state of the water must also be under control with minimal and maximal stimulus figures predetermined, once again this does not have to be in standard thermal units, it may be ohm, volt, or current. The thermal source must also undergo proof of replication, that is voltage and current must be sampled and cited, this with a given rise of stimulus and known volume of water delivered from the intermediate stage under thermally controlled conditions, the apparatus will meet the scientific requirement of replication and control in regards the thermal base line, and thermal tanking.
If the apparatus has proven repeatable to this point, it should be allowed to continue. Otherwise corrective actions must be taken, cited, logged, and the process repeated until proven reliable.
--Here is where it starts to get fuzzy in terms of standard conditions--
The next variable of interest is another volumetric, that is gas. Before any experiment can be allowed to continue a leak testing must be performed, but prior to the leak test a pressure range must be established. That is minimal and maximal pressure differences relative to atmosphere. The apparatus should be kept in a temperature controller environment,IE, and incubator. The incubator itself will have standard conditions which much be met, that is, a range, minimal, maximal cited in a thermal stimulus.Just as before, the incubator must be proven to be within operating range prior to an experiment, this would be cited in the log book as well.
With a proven, thermally controlled environment, the leak test may be allowed to continue. The leak test will have it's own range
Note, if the minimal and maximal range far exceed that of the pressure gain from IR radiation, then an incubator will not be required. However, such a large pressure range is not likely to yield qualitative figures such as a low pressure range. For scientific replication i highly recommend a low pressure range as this will eliminate any doubts that may be evident otherwise.
It's ridiculous to expect a person to log hundreds of data points a minute. But it is foreseeable to use a computer to log and control; simply require a person to sign off on a digital record. It then becomes obvious that a SCADA application is a definitive requirement of such an apparatus. Such a SCADA application should be discussed in great detail, as once established everyone could share their results and control algorithms.
Consider this the standard conditions for experiments. What i have just out lined here will provided hundreds of variables that meet the strict requirements of scientific replication. In addition, everyone will be able to contribute in a positive manor. The data produced by such a system will be useful by many people for years to come.
With such a system, we progress.