Section V, Relays). The duration of a momentary contact closure is 200 mSec for
which the corresponding relay status LED will flash. As a remote totalizer relay, the
contact is closed each time the displayed total is increased by the amount entered into
P-56. As a flow sampler relay, the contact is closed each time the volume of liquid as
set by P-57 and P-58 is pumped. As a time sampler relay, the contact is closed at the
rate of the time period entered into P-59.
The mA output responds to the head or flow (P-50). In the event of fail-safe due to loss
of echo, the mA output will respond as programmed by P-6 and P-74.
When calibrating the HydroRanger I for the OCM function, the empty distance to
transducer (P-3) may be considered and entered as the distance from the transducer
face to the 0 head or no flow reference level. If this measurement is not easily
obtained, P-3 can be estimated and corrected via P-47 . This is referred to as the Auto
Zero calibration and requires the HydroRanger I to compare a physical measurement
(from wall gauge, dipstick or stilling well) to the ultrasonic measurement via P-47. Refer
to Example 6a.
It should also be noted that when operating in the OCM function: percent display,
volume conversion (P-34) and convert display (P-37) are inoperative. Empty calibration
(P-61) must be clear, i.e. 4 hyphens in the display.
Example 6
9" Parshall Flume
Q = 1.98 H
1.53
where Q = flow rate, MGD (million gallons per day)
H = head, feet
- max. flow rate - Q max. = 4.112 MGD
= 4,112,000 gal./day
- max. head - H max. = 1.61
- transducer is mounted 3 ft above the zero flow level
- max. flow rate display = 4,112
i.e.: one count = 1000 gal.
select:
P-1 enter option “3”, units in inches
P-2 enter option “5”, OCM
P-3 enter “3”, zero level distance to transducer
P-4 enter “1.61”, max. head
PL-399 6 – 31
To Next Page
Loading...
