Teledyne 2000A-EU - General purpose thermal conductivity analyzer - Manual (Page 57)

Thermal Conductivity Analyzer Operation 4
4-19 Teledyne Analytical Instruments
4.6.1 Manual (Select/Define Range) Screen
The Manual range-switching mode allows you to select a single, fixed
analysis range. It then allows you to redefine the upper and lower limits, for the
range.
Press Range key to start the Range function.
Select range
mode: MANUAL
Note: If all three ranges are currently defined for different applica-
tion gases, then the above screen does not display (because
mode must be manual). Instead, the LCD goes directly to the
following screen.
If above screen displays, use the
∆∇
arrow keys to Select
MANUAL, and
press Enter.
Select range to run
—> Ш1 Ш2 Ш3 CAL<—
Use the < > keys to select the range: 00, 01, 02, or 03. (04 is for future
expansion.) Then press Enter .
Gas use: O2 — N2
Range: Ø — 16 %
Use the < > keys to toggle between the Range: low-end field and the
Range: high-end field. Use the
∆∆∆∆∆∇
keys to change the values of the fields.
Press Escape to return to the previous screen to select or define another
range.
Press Enter to return the to the Analyze function.
4.6.2 Auto (Single Application) Screen
The Auto screen requires you to select an application (previously defined in
the System function. It then automatically places all ranges previously defined
for that application in queue for automatic range switching.
In the autoranging mode, the microprocessor automatically responds to
concentration changes by switching ranges for optimum readout sensitivity. If the
upper limit of the operating range is reached, the instrument automatically shifts
to the next higher range. If the concentration falls to below 85% of full scale of
the next lower range, the instrument switches to the lower range. A correspond-
ing shift in the DC concentration output, and in the range ID outputs, will be
noticed.