Conversion Equations and Post-processing
Conversion Equations
The physical units measured by the probes are converted into a more easily understood unit of mea-
surement by built-in conversion equations. In the case of the temperature probe, for example, changes
in temperature are measured by fluctuations in electrical resistance by an electrical device called a
Othermistor.� The conversion equation converts the measured resistance value to a temperature unit
(such as degrees Celsius) and produces the converted value on its screen. Each of the analog chan-
nels and the SONIC channel has its own built-in conversion equation.
Post-processing
The data analyzer unit provides the means to perform certain calculations using sampled data when
required. This is called Opost-processing� (processing of data after it is sampled).
This data analyzer unit supports three types of post-processing: first derivative, first and second de-
rivatives, and statistics. Selecting first and second derivatives for post processing, for example, calcu-
lates the first and second derivatives* for the sample data and stores the result into memory. Selecting
statistics calculates the mean, standard deviation, minimum and maximum for the sampled data and
stores them in memory. Calculated data can also be downloaded to a graphic scientific calculator.
* The term Oderivative� here means Otime increment.�
Data Filtering
Static Onoise� can sometimes cause sampled data to become corrupted, making it impossible to ob-
tain accurate results from calculations and analysis. This data analyzer unit includes a data filtering
system that eliminates noise and help to make sure that data is always accurate.
N 2 N |