Turner Designs TD-700, Руководство по эксплуатации, Страница: 19 / 55

TD-700 Laboratory Fluorometer Operating Manual
Page 18
VI. Calibration Overview
A. Why Calibrate?
The TD-700 calibration procedures set the instrument's sample range,
(concentration range) and sensitivity based on a chosen fluorescent
standard or sample. In addition, calibration in the Direct Concentration
mode assigns a digital value to a known standard so that subsequent
standards or samples can be easily referenced to the original. For ex-
ample, during Direct Concentration calibration you can assign a value of
500 to a sample and know with certain confidence that a sample that
reads 250 contains half as much analyte as the original sample (assuming
that the blank reads zero).
B. When to Calibrate
· For greatest accuracy, calibrate before running a new batch of
samples.
· Recalibrate if the ambient temperature changes by +/- 5 ° C.
· Recalibrate after changing lamps, filters, cuvette sizes, or the analyte
you are measuring.
· Verify the need to calibrate by reading a stable, known concentration
standard immediately after calibration and again every few hours to
see if readings have changed significantly. Recalibrate when the
accuracy becomes unacceptable for your study.
C. TD-700 Calibration Options
There are three calibration procedures available on the TD-700:
· Simple Mode- Raw Fluorescence Calibration
· Multi-Optional Mode- Raw Fluorescence Calibration
· Multi-Optional Mode- Direct Concentration Calibration
1. Simple Mode Calibration : In the Simple Mode calibration procedure
the instrument range is automatically set based on the typical
standard or sample chosen. You cannot manually adjust the
instrument range when calibrating in this mode. The chosen sample
will be automatically set to 50% of the maximum value that can be
accurately read by the instrument, (500 out of 1000). Also, there is no
option to read and subtract a blank during this calibration procedure.
2. Multi-Optional Raw Fluorescence Mode : In the Multi-Optional
Mode Raw Fluorescence calibration you may manually adjust the
instrument range by changing the default sample value of 500 to
another number from 100 to 950. If you assign a value higher than 500
to your chosen sample, you will decrease the maximum sample
concentration that can be read and increase the instrument’s
sensitivity and resolution. If you assign a value lower than 500, you
will increase the maximum concentration that can be read and
decrease the instrument’s sensitivity and resolution.
Note: Calibration data will be
stored even after power to the
instrument is turned off.
Note that a separate calibration
is stored for each of the three
modes. For example, if you
calibrate in the Simple Mode,
this calibration remains in
effect until you recalibrate in
the Simple Mode. If you
calibrate in the Multi-Optional
Mode - Direct Concentration,
this will not change the
calibration in the Simple
Mode. Similarly, a calibration
in the Multi-Optional Mode -
Direct Concentration will not
affect a calibration in the
Multi-Optional Mode - Raw
Fluorescence.
Thus, in effect, the TD-700 can
store three separate
calibrations at the same time,
one for each mode. This also
means that when you change
modes, as each mode is a
separate function, you must
calibrate in the mode you want
to use.