RADIOMETER ABL90 FLEX - Measurement - Ph and Electrolytes; Measurement; Checks

ABL90 FLEX reference manual 5. Sensors and optical system
5-21
Measurement – pH and electrolytes
The pH value measured from the sample is calculated as follows, from the
sensor signal of the sample mV
sample
:
sample cal1
cal1
mV mV
pH pH
61,5mV S



The electrolyte concentration in a sample is calculated from the following
equations:
n(E -E )
sample cal1
61,5mV×S
cal1
cc 10
where n is the ionic charge.
The measured value is applied a linear correction:
displayed 1 2
ckck
NOTICE: cCl
–
is compensated for cHCO
3
–
interference by using the measured
pH and
pCO
2
, before the linear correction is applied.
The following parameters are range checked:
 Sensitivity
 Sensitivity drift
 Status
 Sensor response stability
The sensor response stability is defined as the standard deviation of the last 5
updatings of the response.
Measurement
Checks