Simple Level Application
The most common application of the Milltronics ultrasonic level measuring systems is
for simple level monitoring, whereby the material level or space measurement is
displayed. This may or may not include alarms and mA output.
When in the calibrate mode, alarm relays will remain in their prior state. However, they
will respond to measurements taken when “MEAS” is pressed.
Example 1
The application is to obtain a level measurement and corresponding 4 - 20 mA output of
a 30 ft. high vessel. The transducer face is level to the top of the vessel, the empty
level will be at 0 ft. (bottom) and the full level will be at 28 ft. from the bottom (span). A
high alarm is required at 4 ft. from the top (26 ft. from the bottom) and a low alarm is
required at 5 ft. from the bottom. The maximum filling rate is 1 ft./min. The maximum
emptying rate is 1 ft/min, a rate greater than this should set an alarm. In the event of a
loss of echo, the HydroRanger I is to go into fail-safe hold after 2 minutes.
select:
P-1 enter option “3”, units in feet
advance to:
P-2 enter option “1”, material level
P-3 enter “30”, empty distance to transducer
P-4 enter “28”, span
P-5 enter “2”, blanking distance, 30’ - 28’ = 2’
P-6 enter option “2”, 4 - 20 mA output
P-7 enter “2”, display max. 2 digits after decimal
P-8 enter option “1”, relay 1 - alarm function
P-9 enter “26”, relay 1 - alarm ON
(30’ - 4’ = 26’)
P-10 enter “25.5”, relay 1 - alarm OFF
deadband = 0.5’, arbitrary setting
P-11 enter option “1”, relay 2 - alarm function
P-12 enter “5”, relay 2 - alarm ON
P-13 enter “5.5”, relay 2 - alarm OFF
PL-399 6 – 3
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