Model BetaCAP60X100 - Compact Gas Diluter With 3 Inputs Pre-Dilution Systems
BetaCAP60X100 a compact diluter with 3 inputs (two gases to be diluted in a diluting gas), pre-dilution just for an input and flow comparator for self-checking with relative deviations calculation. BetaCAP60X100 is built complying with the principles that inspire the entire Be.T.A. production : equal capillaries, electronic pressures control and manifold construction in highly corrosion-resistant materials. Very similar to the BetaCAP60-3G model, is distinguished only by the addition of a module pre-divider by 100, inserted in series at the TG1 gas inlet (measurand).
Both inputs (TG1 and TG2) can be diluted in the range 0 … 100% in 60 steps. The TG1 input can be diluted over a further 60 steps in the range 6000 : 1 … 100 : 1. While the 0 … 100% range is designed for emissions analyzers, the higher dilutions allows testing analyzers used for Air quality monitoring networks in ppb using cylinders containing several hundred ppm.
As for the rest of the Be.T.A. production, the “continuous” mode is available, which will leave no regrets for users accustomed to using MFC systems, who will enjoy much higher stability in short, medium and long term.
BetaCAP60X100 enters in direct competition with MFC systems which, before its recent arrival, almost dominated the world of tests on air quality analyzers.
It also benefits from numerous advantages :
- immediately upon power up and for years it presents highly repeatable characteristics, even if subject to the typical stresses of field instrumentation
- the correct proportionality of the flows (linearity of the diluter) is already very accurate even before the metrological calibration. This is due to the fact that the selection of “equal capillaries” is intrinsically simpler than the correction with broken lines to be defined
- The use of “discrete steps” has all the advantages of digital technology, but we have also made use of this in continuous mode so as not to change the habits of former users of MFC systems.
- Minimum dimensions and maximum strength (therefore portability) are obtained with the manifold construction on and a careful use of the available spaces.
The three modules that make up BetaCAP60X100 have been highlighted:
- The BetaCAP1A100 module has the function of pre-diluting the measuring gas (TG1) on command (ON / OFF). When activated it produces a fixed pre-dilution with a 100 : 1 ratio. De-activating EVBy the TG1 input is connected to the next module without changes.
- The BetaCAP60-3G module follows, abundantly described on the corresponding page of this site. This module dilutes, according to the User’s commands, two gases or mixtures (TG1 and TG2) in a diluent gas (TG0). Each entrance can pass from 0 to 60 capillaries, while all the capillaries are affected by one of the three incoming gases.
- The third module is optional : a 5-scale flow meter. It works by measuring the differential pressure (draft range) produced by the pressure drop on the selected capillaries groups. The module is normally bypassed and is inserted only during the calibration process, described below
BetaCAP60X100 has a particularly luky combination of features regarding the groupings of installed capillaries:
- each group with equal number of capillaries is installed in double (two per type)
- the numerical progression of capillaries installed in the different groups is 2 ^ n: the different groups have a double numerical consistency with respect to the previous
Observing the situation with a minimum of attention, the possibility of comparing groups of equal capillaries (subject to the same pressure must handle equal flows) is quite obvious, but also the possibility of comparing pairs (in parallel) of groups with x ^ n capillaries with single groups with (x + 1) ^ n capillaries (same total number of capillaries)
A function is available (created for local execution and for PC-managed execution) that uses the CAP60 module described above to perform a series of programmed comparisons, from which the flow deviations of each group are calculated with respect to the correct proportions. The operation takes its validity from the consideration that the dilution ratio is a pure number (not a quantity) and that its value does not change by multiplying by the same constant the value of the two flows (diluting gas flow and diluted total flow) which in the ratio they define it.