ABB AW101, Instruction Manual

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Water Hardness Analyzer
AW101 Testomat 4 Description of Displays and Operating Features
10 IM/AW101 Rev. C
4.12 Logic Functions of Limit Value Outputs LV1 and
LV2
The logic limits are:

Logic function 0, Duration
Output relay LV1 or LV2 energizes when the measured
value rises above limit value LV1 or LV2. If the measured
value falls below the limit value LV1 or LV2 the relevant
relay de-energizes again.

Logic function 1, Impulse
If the measured value rises above limit value LV1 or LV2,
the relevant output energizes for a set time t. Independent
of the time taken for the limit value to rise above the set
limit, the relevant output always remains in the ON position
for the set time.

Logic function 2, Interval
If the measured value rises above one limit value, the
relevant output energizes at intervals of the set time
(Impulse/Pause).

Logic function 3, Two-point
If the upper limit value LV1 is exceeded, the output relay
LV1 energizes. If the lower limit value LV2 falls below the
set limit, output relay LV1 de-energizes.
Output relay LV2 energizes according to the programmed
logic function.
This function is possible only if different values are
selected for LV1 and LV2. For example for LV1 = 0.2 °dH
and for LV2 = 0.1 °dH.
4.13 Low-level Reagent Alarm (BOB function)
In certain steam boiler installations, the possibility of an
unsupervised boiler operating with a depleted supply of reagent
has safety implications (because untested sample is allowed to
flow through the boiler system). To overcome this problem, the
AW101 employs a programmable low-level reagent alarm
operation function. This monitors the reagent constantly and an
alarm is triggered if the available reagent quantity falls below the
quantity required for 72 hours usage.
4.14 STOP Function
The active analysis cycle can be interrupted by pressing the
STOP/Standby key on the display pad. The cycle can be
interrupted remotely/automatically using the STOP relay.
4.15 Water Meter
For quantity-dependent analysis triggering it is necessary to
connect a water meter to the IN2 input. Program the
corresponding water meter rating under menu item WATER
METER or enter the impulse number of the turbine water meter.
4.16 Analog Output
Another possibility for monitoring the analysis is the connection
to a process recorder or supervisory system. For this purpose
the unit is equipped with a programmable current output.
A maximum working resistance of 350
 
must not be
exceeded. In situations where interferences might occur and for
very long cables (approximately 20 m [65 ft.]), use a screened
cable.
BOB on: Continuous monitoring of the residual reagent
quantity. ALARM message when the available
quantity falls below the minimum quantity for the set
period – 'Alarm' flashes, the Alarm output is
energized.
BOB off: Without BOB function – the residual reagent
quantity is monitored only for the minimum quantity
(10% level).
Example: BOB-Duration = 72 Hours.
Number of analyses per hour = 10.
Necessary quantity of reagent for 72 h = 72 h x 10.
Analysis/h x (3 x 30) µl/Analysis = 64.8 ml.
(Corresponds to approximately 13% of a full level
bottle).
Fig. 4.4 Reagent AW10903
Example Reagent AW101903, 0 to 20mA
CaCO
3
mA
20 179
12 107.4
8 71.6
4
0
0