Page 12 - Vol.39-No.6

IRRIGATION

EFFICIENT IRRIGATION STARTS WITH

THE FLOW METER

Reading a flow meter is much like reading purposes, and continue to accumulate the
the speedometer and odometer on a car. total amount of water flowed through the
lifetime of the meter.
A flow meter provides
two valuable pieces of
information:
1) The flow rate – This is the pumping
rate and typically appears in gallons per
minute (GPM), though other units of meas-
ure are available. The flow rate is similar to
a speedometer on a car. The flow rate on a
meter is showing the speed that water is
currently being pumped, while the rate on a
car’s speedometer is telling how many miles
per hour the car is travelling. Knowing the
volume of water being pumped per time In addition to the main totalizer, some
interval (think seconds, minutes, hours) electromagnetic flow meters, such as the
tells you how much water you are getting Seametrics AG3000 and AG90 offer addi-
from your water source. This valuable piece tional batching totalizer features that can
be used like the trip-o-meter on a car.
Various methods are used to apply water of information is the actual pumping ca- These batching totalizers are resettable and
to crops. Gravity irrigation systems use pacity (GPM) and helps growers determine can be used to measure the total amount
on-field furrows or basins to move water how many acres of irrigating their flow rate of water pumped between two points in
across the field through gravity means only. will support. This information is valuable time. If your flow meter does not offer
Over the past several decades, many ir- to keep record of on regular intervals. The a batching totalizer, the seasonal water
rigators have converted from gravity to flow rate information can also be used to usage can still be easily calculated by sub-
pressurized irrigation systems. Pressurized evaluate yearly or seasonal changes due tracting your beginning of season reading
irrigation systems continue to gain popular- to water table drawdown, aquifer decline, from your end of season reading = season
ity and apply water under pressure through pump wear and overall system health. long amount of water volume pumped. The
pipe or tubing to the crops and include: process of reading a flow meter and calcu-
center pivot, drip, and sprinkler irrigating. lating seasonal usage is further simplified
Today over 70% of irrigation systems in if being read through a telemetry system
the U.S. are pressurized. In many field con- dashboard.
ditions, pressurized irrigation systems are
more water-use efficient than gravity sys- Ensure your flow meter is in good working
tems, with less water being lost to runoff order before the irrigation season begins.
and evaporation. No matter your method Just like your truck or car, your flow meter
of irrigating, an efficient irrigation system will need occasional maintenance. While
should include a working flow meter. mechanical meters have moving parts to
wear out, electromagnetic flow meters
When the pump is on, water is moving have no moving parts making them low
and costs are being incurred. Many irriga- maintenance and an overall lower cost of
tion systems use both electricity and fuel, ownership. If your electromagnetic meter
making the cost of running the system is powered by a battery, you will want to
very expensive. Flow meters not only tell keep record of the last time the battery
irrigators how much water they are using, was replaced, and ensure the meter has a
they are also a valuable tool that can be working battery before irrigation season
used to determine the health of an irriga- begins. Many electromagnetic flow me-
tion system and alert an irrigator if there is ters for irrigation now offer up to a five
an issue, leak, or power outage. Metering year battery life. Refer to the maintenance
and monitoring an irrigation system can manual for your flow meter to understand
ensure efficiency and prevent costly system expected battery life as indicated by the
damage and failures. manufacturer.
2) The flow totalizer – This is the to-
There are several types of flow meters tal amount of water pumped and typi- A flow meter is just one component of an
available for irrigation today, with electro- cally appears in acre feet (AF) or gallons entire irrigation system. The cost to pur-
magnetic meters now the most popular (GAL), though other units of measure are chase and maintain a flow meter is a small
choice. Many electromagnetic flow me- available. The flow totalizer is similar to fraction of the cost of an entire system, yet
ters are telemetry compatible, enabling the odometer on a car. The flow totalizer they provide valuable information about
growers to monitor, be alerted to various shows the total amount of water pumped water use and irrigation system efficiency
flow anomalies, and in some cases control through the meter. Most flow meter to- enabling irrigators to make smart decisions
the irrigation system via cell phone, iPad, talizers are non-resettable for regulatory on managing their fields.
laptop or desktop computer in real-time.

10 Vol. 39 No. 6
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