Hach PHOSPHAX sigma Manuel D'utilisation De Base page 128

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. For the feeding of the reagents C and D, a two-
channel pump (two pump cassettes) is used, for the other pumps a one-
channel pump (one pump cassette) is used.
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.
N O T I C E
For a long-term shutdown (over 48 hours) the
pump cassettes must be released in order to relieve the dosing hoses — but
because of the return flow risk the hoses should first be removed from the
screw caps (canister lids)! Please observe during the handling of the reagents the
safety notes under
section Exchange of the reagents.
Figure 9 Dosing pump head during roller exchange
Pump cassette
Pump roller
English 128
Dosing- and valve hoses
All dosing- and valve hoses for one assembly are in the annual wear
part set and must be clearly distinguished by unlosable, colored marks.
N O T I C E
For all work on dosing hoses, the hoses must always be pulled out of the
respective canisters as the first action and inserted again as the last action!
(Return flow hazard). Please observe during the handling of the reagents the
safety notes under section Exchange of the
Dosing hoses
The hoses called dosing hoses are those routed via the dosing pumps.
The dosing hoses may only be placed on the respective dosing pump
intended for it. After 3 months, the sample dosing- and drain hose must
be exchanged and the pump rollers coated with silicone paste. For the
reagent dosing hoses (A, C and D) this is only required every 6 months.
Valve hoses
After 6 months, the valve hose (connection between hose pinch valves 1
and 2) is replaced
Digestion cuvette
C A U T I O N
To prevent burns, allow the digestion cuvette to cool down for at least 30 minutes
before it can be serviced/replaced.
The combination of digestion unit, cuvette and photometer is the heart of
this device. It enables the quick and thorough mixing of the sample with
the digestion agent and the other reagents, guarantees a fast heat-up
and cool-down and guarantees a reliable and precise measurement.
reagents.