Turner Designs TD-700, Руководство по эксплуатации

Страница: 47 / 55

TD-700 Laboratory Fluorometer Operating Manual
Page 46
G. Error6
Calibration is bad. This may occur if the actual value you entered for a
standard does not match its fluorescence reading in comparison with one
or more of the other standards. For example, you put in a standard you
say has an actual value of 10 and it reads 150, and you put in another
standard you say has an actual concentration of 5 and it reads 200. Press
<ESC>, then <1> to abort the calibration; calibrate again using properly
diluted and labeled standards.
H. HOME Screen Displays OVER, or Negative Numbers
1. OVER
If the HOME screen displays “OVER” (and the lid is closed), this means
that the sample reading is too high for the instrument’s light detector to
read at the current level of sensitivity, i.e., sensitivity is set too high (raw
fluorescence reading >1000).
If you see OVER, check the reading in the Diagnostics sequence. If it is
>1000, make sure the proper filters are installed. Examine the filters for
damage: freckling of mirrored surfaces, cracks, etc.
If you are reading samples of high concentration, you can dilute them until
you get an on-scale reading. Or, if you wish to reduce sensitivity, calibrate
the unit again. If you are in the Direct Concentration calibration procedure,
choose a higher Max range conc. or a more concentrated “high” standard.
If you are using the Raw Fluor. Calibration Procedure, use a more concen-
trated standard and/or chose a lower value for the sample setting if you are
in the Multi-Optional Mode.
NOTE: On rare occasions, you might see “-OVER”. This means that the
raw fluorescence reading is less than -1000. This might happen if you
calibrated with an extremely high Blank.
Do not leave the instrument
reading "OVER" for an extended period of time (several minutes).
2. Negative (-) numbers
If the HOME screen is displaying a negative number, it means that the
sample is reading less concentrated than the Blank. This might occur in a
case where you calibrated with a high Blank; or it might occur if the Blank
is reading negative due to instrument drift. To cure, if you are in the Raw
Fluorescence Calibration Procedure, you can use the Reset Blank to Zero
function. Or, you can recalibrate.
I. Blank Level Error
If the blank level is too high when the user tries to re-blank the instrument
from the HOME screen, this error may occur. Most likely this error is a
result of using the wrong solution to blank with. To remedy, use the correct
blank solution. If the error persists, recalibrate.
Error6: Bad
Calibration
G.
Error: Blank
level too high
I.