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P a g e
Step 1
Set wavelength by using keypad numbers or left and
right arrows.
Press the down arrow key.
Step 2
Select the mode, Factor (user entered), Standard
(factor is calculated from a calibration sample), or
Negative Factor (user entered, without a sign) using
the left and right arrows.
Press the down arrow key.
Step 3 (if Factor is selected)
Enter the Factor using the keypad numbers. Range
0.001 to 9999. Use the C button to delete the last digit
entered.
Press the down arrow key.
Step 3 (if Standard is selected)
Enter the concentration using keypad numbers. Range
0.01-9999. Use the C button to delete the last digit
entered.
Press the down arrow key.
Step 4 (if Negative Factor is selected)
Enter a negative factor, without a sign, using the
keypad numbers. Range 0.001 to 9999. Use the C
button to delete the last digit entered.
Press the down arrow key.
Step 5
Units: The user can enter a text string up to 8
characters long. To access a list of pre-defined units
press the Options key
and then use the
left/right arrows (µg/ml, µg/µl, pmol/µl, mg/dl, mmol/l,
µmol/l, g/l, mg/l, µg/l, U/l, %, ppm, ppb, conc or none).
These units can also be edited once OK is pressed.
This screen also allows the number of displayed
decimal points (DP) to be selected, from 0 to 2. Note
that the result will always be fixed to 5 significant
figures regardless of how many decimal points are
selected (so 98768.2 will display as 98768 even with 1
decimal point selected). Press OK
to store the
chosen parameters or Cancel
.
Concentration
This makes simple concentration measurements on samples, by measuring the amount of light that has passed through a
sample relative to a reference (this can be air). Concentration is obtained by multiplying the measured absorbance at a
specific wavelength by a factor. The factor may be known in advance, or may be calculated by the instrument by
measuring a standard of known concentration.
The procedure is as follows:
