triOS nanoFlu - Page 23

21D01-060en202008 Manual nanoFlu
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nanoFlu // Calibration
Before recording measurement values, check the zero value of the sensor with their reference solutions. If
necessary, determine a new zero value (see chapters 6.2.1 and 6.3.1).
Local calibration is adjusted by means of a linear equation. Two constants are required for this: the scaling
factor and o󰀨set, which are used according to the following equation:
A = parameter - oset
B = A ∙ scaling
With A being the parameter output, which is output by the nanoFlu.
A o󰀨set corrected value
Oset o󰀨set value
B customer-calibrated parameters
For local calibration, at least two data points, i.e. a laboratory value and a sensor value, are required. The eas-
iest way to do this is to use a non-contaminated sample and a contaminated sample.
1. The non-contaminated sample is used to determine the o󰀨set. To do this, immerse the uorometer in
the uid that is not contaminated. In this specic case, the signal gives the value of the o󰀨set directly for
local calibration.
oset = measuredvalue1
If a non-contaminated sample is not available, the equation in point 5 below o󰀨ers another option.
2. Now immerse the sensor in the contaminated medium and note down measuredvalue2, which is output
by the uorometer, and do a laboratory analysis of the sample.
3. Make a diagram like the one shown below and connect the two data points with a straight line. The slope
of the straight line is the scaling factor.
The customer calibration can be used as a ne adjustment of the sensor for special media
and supplements the manufacturer calibration.