wtw NitraLyt 700 IQ, Operating Manual, Page: 30 / 61

Calibration and measuring NitraLyt
®
700 IQ
4 - 10 ba75397d03 12/2004
4.1.6 Calibration procedure, 1 point ref. (2)
The 1 point ref. (2) 1-point calibration is carried out with the sample and
in two main steps, each of which is started with
c
.
Note
Determine the calibration value and take the sample from the aeration
tank after the aeration phase is finished. The nitrate concentration is
highest at this point of time. At the end of the phase without aeration
the nitrate content can decrease to a value that lies close to the detec-
tion limit. It does not make sense to calibrate in this range.
Note
Determine the chloride content together with the reference value for the
nitrate content in this calibration procedure.
Operating steps during
step 1
Note
During the subsequent determination of the reference concentration in
the laboratory you can use the sensor for measuring again by simply
abolishing the maintenance condition.
The sensor continues to use the old calibration data. The reference
voltage determined in step 1 of the calibration is not lost. It remains
stored until step 2 of the calibration is completed. It does not have to be
noted and entered again.
Display Explanation
Cal.: 1 POINT REFERENCE (2)
Step 1: Reference voltage is
being determined Confirm with
g
.
* Rinse electrode.
* Immerse electrode in sample.
* Observe conditioning time of 15
minutes. Before starting the calibration the
sensor should be immersed in the
test sample for conditioning for at
least 15 min.
Start the measurement with
g
.
This step determines and stores
the reference voltage.
As soon as a stable measured
value is recognized, the next dis-
play appears.
Step 1 finished. Switch to
the measured value display
with 2x 'OK'. After det. The
reference concentration,
start calib. step 2 with 'C'. Step 1 of the calibration is fin-
ished. Press
g
twice to switch to
the measured value display. The
sensor is in the maintenance con-
dition.