7
Calibration
To properly maintain the accuracy of the Mark III refractometer, calibration of the instrument on a
routine basis is recommended. Prior to calibration, it is extremely important to completely clean the
prism surfaces so no sample residue is present. Any residue on the prism surfaces will adversely
affect the accuracy of the calibration.
Calibration options are either Set Point or Span Point. Set Point calibration is performed using
distilled water as the calibration standard. Reichert recommends performing the Set Point calibration
daily. Span Point calibration is performed with distilled water and up to 6 additional calibration
standards. It is not essential to calibrate at every available point. Span Point calibration with
distilled water and at least one calibration standard is recommended to ensure accuracy across
the reading range of the instrument. Span Point calibration standards can be chosen to closely
match the reading range of the product being analyzed.
Set Point Calibration
- Advance to the Calibration, Adjust Set Point menu op
tion, and press .
- Apply distilled water as the calibration standard, as de
scribed under Sample Analysis, and allow to equilibrate
to the instrument temperature.
- Adjust shadowline to the center of the “X” pattern and press to
calibrate or to cancel.
- Upon completion the display will revert to the Calibrate menu option screen.
- Press to return to the reading mode.
Menu Options
-
Calibrate
- Adjust Set Point
- Adjust Span Point
- Advanced Options
- Exit
1.33299
Distilled Water
Position shadowline
on center of
“X” in reticle.
Press READ when ready
or SELECT to cancel
Temp
o
C
Span Point Calibration
The Span Point calibration option allows for up to six additional calibration points. These points
can be chosen to either calibrate across the entire reading range of the instrument, or to closely
match a specific range where samples are typically read. The instrument does not have to be
calibrated at every available point. If you have specific requirements, Reichert offers NIST certi
-
fied calibration fluids as an accessory to this instrument. One bottle of NIST certified calibration
oil, catalog number 13K41330 is included with the instrument.
Note:
Prior to performing the Span Point Calibration process, Set Point Calibration must be
completed.
- Advance to the Calibration, Adjust Span Point menu
option, and press .
- Follow the displayed instruction to either activate or
inactivate a calibration point. Points preceded by * are
active and those preceded by - are inactive. The choice
of these points are dictated by which calibration standards
are available at the time of calibration.
- Proceed with the calibration process by advancing to
Continue on the display screen and pressing .
- As the active calibration values are displayed, add that
calibration fluid and allow to temperature equilibrate
Position the shadowline on the center of the “X” pattern
and press to calibrate or to cancel. Promptly
clean the calibration fluid from the instrument to remove
all residue.
- The above step will be repeated until all active points are
calibrated.
- After the last active point has been calibrated the display
will return to the Calibrate option screen.
- Advance to Exit and press .
- Press to return to the reading mode.
Menu Options
- Calibrate
- Adjust Set Point
- Adjust Span Point
- Advanced Options
- Exit
Span Calibration
* 1.40235
* 1.45746
- 1.48989
- 1.51432
- 1.57230
- 1.63039
Continue
Exit
* = Active
- = Inactive
l l to choose
SELECT to toggle
Menu Options
- Calibrate
- Adjust Set Point
- Adjust Span Point
- Advanced Options
- Exit
1.40235
Position shadowline
on center of
“X” in reticle.
Press READ when ready
or SELECT to cancel
Temp
o
C
