Data Acquisition system (DAS) and APICOM T400 Ozone Analyzer Operator’s Manual
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7.4.2.1. EditiNg DAS Parameters
Data parameters are types of data that may be measured and stored by the DAS. For
each Teledyne API analyzer model, the list of available data parameters is different,
fully defined and not customizable. Appendix A-5 lists firmware specific data
parameters for the T400. DAS parameters include things like O
3
concentration
measurements, temperatures of the various heaters placed around the analyzer, pressures
and flows of the pneumatic subsystem and other diagnostic measurements as well as
calibration data such as slope and offset.
Most data parameters have associated measurement units, such as mV, ppb, cm³/min,
etc., although some parameters have no units. With the exception of concentration
readings, none of these units of measure can be changed. To change the units of
measure for concentration readings See Section 6.8.6.
Note DAS does not keep track of the units (i.e. PPM or PPB) of each
concentration value and DAS data files may contain concentrations in
multiple units if the unit was changed during data acquisition.
Each data parameter has user-configurable functions that define how the data are
recorded:
Table 7-3: DAS Data Parameter Functions
FUNCTION EFFECT
PARAMETER
Instrument-specific parameter name.
SAMPLE MODE
INST: Records instantaneous reading.
AVG: Records average reading during reporting interval.
MIN: Records minimum (instantaneous) reading during reporting interval.
MAX: Records maximum (instantaneous) reading during reporting interval.
SDEV: Records the standard deviation of the data points recorded during the reporting interval.
PRECISION
Decimal precision of parameter value (0-4).
STORE NUM.
SAMPLES
OFF: Stores only the average (default).
ON: Stores the average and the number of samples in each average for a parameter. This
property is only useful when the AVG sample mode is used. Note that the number of samples
is the same for all parameters in one channel and needs to be specified only for one of the
parameters in that channel.
Users can specify up to 50 parameters per data channel (the T400 provides about 40
parameters). However, the number of parameters and channels is ultimately limited by
available memory.
Data channels can be edited individually from the front panel without affecting other
data channels. However, when editing a data channel, such as during adding, deleting or
editing parameters, all data for that particular channel will be lost, because the DAS can
store only data of one format (number of parameter columns etc.) for any given channel.
In addition, an DAS configuration can only be uploaded remotely as an entire set of
channels. Hence, remote update of the DAS will always delete all current channels and
stored data.
