YSI 9300 Photometer - Manual (Page 12)

9
Locking System Mode Settings (9500 Only)
It is possible to 'lock’ the system settings so that these cannot be tampered
with or altered accidentally during use. This is important, for example, where
it is necessary to verify that tests have actually been carried out at a particular
time or date, or where procedures always require the use of a sample number
or dilution factor.
The instructions for locking the settings are not included in this manual; these
are provided to photometer owners or system administrators on formal
request to YSI’s Technical Support department (
[email protected]
).
Rounding (9500 Only)
In the normal default setting, the photometer will round test results
appropriately for the resolution of the test. The rounding applied differs for each
parameter depending on the shape of the calibration curve. This ensures the
optimum precision and accuracy of each test procedure. For normal purposes it
is strongly recommended that the instrument be left in the default setting.
However, for certain analytical applications, it may be useful to switch off the
rounding to display the result in unrounded form. This may be the case, for
example, when carrying out statistical evaluations of test methods where it is
necessary to use the data in calculation of standard deviation or distribution
data.
Time-Out (9500 Only)
As a power-saving measure, in normal use, both the 9300 and 9500 photometers
automatically switch off five minutes after the last key is pressed.
The 9500 photometer may be switched to ‘Long’ time-out which allows 15
minutes before shut-down or ‘Off’ which allows continuous use. This is
particularly useful when powering the instrument through the USB interface.
Edit User Defined Tests (9500 Only)
Users may wish to develop their own test methods and store calibrations on
the photometer. The 9500 has the facility to store up to 30 user-defined
calibrations. See ‘User Defined Tests’ below for full instructions.