BOB operation (operation without permanent
supervision)
BOB (operation without permanent supervision) is a safety relevant
feature when using the instrument as a water hardness monitoring
unit for monitoring steam boiler plants in accordance with TRD 604.
If the BOB function has been programmed, the instrument
continuously checks the available amount of indicator. A measuring
value of 0.083 °dH (= 0.015 mmol/l alkaline earth ions) is decisive for
the calculation of indicator consumption per analysis. If the residual
amount is insufficient for the set BOB period (programmable 24 - 120
h), an alarm message is output.
▼▲
BOB on: Continuous monitoring of the residual amount of indicator.
ALARM message "low indicator level" when the amount of indicator
falls below the minimum quantity for the BOB time period: BOB
flashes, the ALARM output is switched.
BOB off: No BOB function. Monitoring of the residual amount of
indicator only to minimum quantity (filling level 10 %)
Example:
BOB time period = 72 hours
Required amount of indicator for 72 h = 72 h x 10 analyses/h x (3 x
30) μl/analysis = 64.8 ml.
(This corresponds to a filling height of approx. 13 % for a 500 ml
bottle)
Using BOB operation
NOTE
BOB operation is not possible with the operating mode "volume
Only select the operating mode "time-controlled"!
Switch functions of the limit value outputs LV1 and LV2
In
, select
=>
=>
Select "FUNCTION ON"
Enter the time period in hours (h) under "BOB DURATION"
Press "ENTER" to confirm the entry
control"!
Number of analyses per hour = 10
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