Liquiline CM44P
Calibration
Hauser
131
Use calibration solutions that are suitable for the measuring task. Examples of solutions
which are commonly used include:
Potassium dichromate, K
2
Cr
2
O
7
A solution of 182 ml 0.1N K
2
Cr
2
O
7
, diluted to one liter, has an absorbance of approx. 10
OD at 280 nm. By diluting the solution, you can produce a series of calibration solutions
which you can use to adjust the measuring point.
AU = OD*OPL[cm]
AU ... absorbance units, OD ... optical density, OPL .... optical path length
Instead of potassium dichromate you can also use your process medium for
calibrating/adjusting and for application calibration. Here, also produce a series of
dilutions of known concentration and determine the absorbance in the laboratory.
11.1.2 Easycal
Easycal enables you to perform a calibration/an adjustment which is traceable to NIST
without any liquid standards.
Detector with Easycal: function
1
2
3
4
A0033709
95
Filter in "out" position
1
NIST-traceable filter (high)
2
Locking screw
A0033708
96
Filter in "in" position
3
Positioning pin
4
Lens assembly
Every Easycal device has two traceable filters - one filter with a nominal 0.5 AU and
another filter with 1 AU (absorbance unit) - which are placed individually or together in
the device measuring path. These filter(s) are scanned with traceable testing equipment
and the actual absorbance at individual wavelengths is determined.
It is very important that you use the actual values of the optical Easycal filter. These values
are given in the calibration certificate supplied.
‣
Enter the absorbance values:
Menu
/
Setup
/
Inputs
/
Photometer
/
Extended setup
/
Measurement channel
/
Calib. settings
/
EasyCal
=
Yes
,
NIST filter high
and
NIST
filter low
.
