Hach-Lange AMTAX inter2 Basic User Manual - Manual (Page 104)

English 104
to the hose pinch valves and supplies the analysis section constantly
with a current waste water sample. In the measurement operation, the
sample is first delivered via the left-hand pump P1 into the stirrer vessel.
After 120 seconds, the two reagents A and B are additionally dosed in
precisely defined quantities via the right-hand pump P2. After mixing in
the stirrer vessel, the solution flows through the cuvette, the pumps are
switched off and the color reaction begins. In the cuvette, the
ammonium-specific indophenol blue (yellow-green-blue) coloring now
forms; its intensity is photometrically measured using the two-beam,
two-filter method, whereby the influence of the ambient temperature is
electronically compensated for via a temperature sensor.
Calibration (approximately 8 minutes)
An automatic calibration is performed at freely selectable intervals.
Instead of the sample, a null and a standard solution go one after the
other into the stirrer vessel. As part of this two-point calibration, reagent
ageing and dosing fluctuations are compensated for in order to
guarantee as high an accuracy as possible. After each reagent or dosing
hose change, a calibration must be triggered.:
Auto-cleaning (approximately 10 minutes)
Note: Please observe during the handling of the reagents the safety
notes under
section Exchange of the reagents .
Note: The cleaning solution LCW 819 has been specially developed for
use in the AMTAX inter 2. Other cleaning solutions that are too strong
attack the hoses and can lead to precipitation!
The cleaning solution specially developed for the AMTAX inter 2 is
supplied ready-made in a transparent 250 mL PE bottle, which allows
the fill level to be clearly identified from outside. It is placed to the right of
the stirrer vessel behind the holder.
Auto-cleaning is performed at freely selectable intervals; it covers the
entire sample path through the device and removes impurities as far as
possible in all affected hoses and glass parts.
Dosing pumps
The two hose dosing pumps used are responsible for the transport of all
fluids. They are stepper motor-controlled and variable in speed and
direction of rotation. The dosing hoses are routed with the help of pump
cassettes via the pump rollers.
Wear on the pump rollers is indicated by strong groove formation, which
can lead to defective dosing. In this case, the exchange of the pump
rollers is recommended as a precaution.
Note: The pump cassettes must be exchanged annually!
Figure 9 Dosing pump head during roller exchange
Overflow vessel
Note: Please observe during the handling of the reagents the safety
notes under
section Exchange of the reagents .
Pump phase Duration
Purge with sample 120 seconds
Mixture of sample and reagents 40 seconds
Reaction time and average value formation 140 seconds
Waiting time (with 10-minute measurement interval) 300 seconds
1 M3 countersunk screw 4 Cylinder pin (axle)
2 Cover disk 5 Pump cassette
3 Pump roller