Matheson 819 Series, Operating Manual

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26
Collecting Data:
The RS-232 output updates to the screen many times per second. Very short-term
events can be captured simply by disconnecting (there are two telephone symbol
icons at the top of the HyperTerminal® screen for disconnecting and connecting)
immediately after the event in question. The scroll bar can be driven up to the
event and all of the data associated with the event can be selected, copied, and
pasted into Microsoft® Excel® or other spreadsheet program as described below.
For longer term data, it is useful to capture the data in a text file. With the desired
data streaming to the screen, select “Capture Text” from the Transfer Menu.
Type in the path and file name you wish to use. Push the start button. When the
data collection period is complete, simply select “Capture Text” from the Transfer
Menu and select “Stop” from the sub-menu that appears.
Data that is selected and copied, either directly from HyperTerminal® or from
a text file can be pasted directly into Excel®. When the data is pasted it will all
be in the selected column. Select “Text to Columns...” under the Data menu in
Excel® and a Text to Columns Wizard (dialog box) will appear. Make sure that
“Fixed Width” is selected under Original Data Type in the first dialog box and
click “Next”. In the second dialog box, set the column widths as desired, but the
default is usually acceptable. Click on “Next” again. In the third dialog box, make
sure the column data format is set to “General”, and click “Finish”. This separates
the data into columns for manipulation and removes symbols such as the plus
signs from the numbers. Once the data is in this format, it can be graphed or
manipulated as desired.
For extended term data capture see page 27.
Data Format:
The data stream on the screen represents the flow parameters of the main mode
in the units shown on the display.
For mass flow meters, there are five columns of data representing pressure,
temperature, volumetric flow, mass flow and the selected gas.
The first column is absolute pressure (normally in psia), the second column is
temperature (normally in °C), the third column is volumetric flow rate (in the
units specified at time of order and shown on the display), and the fourth column
is mass flow (also in the units specified at time of order and shown on the
display). For instance, if the meter was ordered in units of scfm, the display on
the meter would read 2.004 scfm and the last two columns of the output below
would represent volumetric flow and mass flow in cfm and scfm respectively.
+014.70 +025.00 +02.004 +02.004 Air
+014.70 +025.00 +02.004 +02.004 Air
+014.70 +025.00 +02.004 +02.004 Air
+014.70 +025.00 +02.004 +02.004 Air
Pressure Temp Vol. Flow Mass Flow Gas
819-Series Mass Flow Meter Data Format
Note: On units with the totalizer function the fifth column will be the totalizer
value, with gas select moving to a sixth column.