ABB AW101

Water Hardness Analyzer
AW101 Testomat 1 General
2 IM/AW101 Rev. C
1 General
The AW101 has been developed as a simple device to monitor
the quality of water from softeners. Applications include
laundries, utility boiler plants, soft drinks factories, brewing, food
processing and potable water plants. It provides an alarm for
high hardness that starts an automatic regeneration of the ion
exchange beds used most commonly in these applications.
The AW101 uses one of four reagents that changes from green
to red at a predetermined water hardness level. The reagent is
added to a known volume of sample via a small pump until a
color change takes place. The volume of reagent required to
bring about this reaction (monitored photo-electrically) indicates
the level of hardness of the water sample. The AW101 also
provides an analog signal, with a range determined by the
choice of one of the four reagents available.
The digital display on the front of the monitor and the analog
output show the value of the last analysis cycle.
Three alarm outputs are provided – two concentration alarms for
control purposes and one alarm to drive an audible signal
device. There are also inputs for a flow device and suspension of
the flow cycle.
1.1 Reagents Available for AW101
The available ranges are determined by the choice of
appropriate reagents. A summary of the different possibilities are
shown in Table 1.1.
Parameter/Type of Reagent
Water Hardness
AW101901
(TH2005)
Water Hardness
AW101 902
(TH2025)
Water Hardness
AW101903
(TH2100)
Water Hardness
AW101904
(TH2250)
Unit
°dH
(Resolution)
0.05 … 0.50 (0.01) 0.25 … 2.50 (0.05) 1.0 … 10.0 (0.2) 2.5 … 25.0 (0.2)
°F
(Resolution)
0.09 … 0.89 (0.02) 0.45 … 4.48 (0.1) 1.79 … 17.9 (0.4) 4.48 … 44.8 (0.4)
ppm CaCO
3
(Resolution)
0.89 … 8.93 (0.2) 4.47 … 44.7 (0.9) 17.9 … 179 (3.8) 44.7 … 447 (3.8)
mmol/l
(Resolution)
0.01 … 0.09 (0.01) 0.04 … 0.45 (0.01) 0.18 … 1.79 (0.04) 0.45 … 4.48 (0.04)
Table 1.1 Reagents Available for AW101
Note.
 A consistently reliable result can only be guaranteed by the AW101 with the use of original ABB reagents. Failure or
problems which are caused by the use of different indicators are not covered by the warranty.
 When monitoring hardness, larger quantities of heavy-metal ions in the softened water can affect the color reaction,
especially iron above 0.5 mg/l, copper above 0.1 mg/l and aluminium above 0.1 mg/l (brownish-red color indication).
Measurement should be made within the range of 4 … 10.5 pH.
 At a concentration of more than 100 mg/l of CO2 in the water, the excess must be removed by installing an appropriate
debubbler in the feed water line to the AW101 unit.