By Norman Bartlett Creative Sensor Technology 1. Irrigator’s View of Landscape Irrigation “ We are beautifying the world” Public’s View “You are wasting

CST Flow Sensor Basics

ByNorman Bartlett

Creative Sensor Technology

Creative Sensor Technology 2

Irrigator’s View of Landscape Irrigation“ We are beautifying the world”

Public’s View “You are wasting water, our precious and

dwindling resource”


REASON #1 TO MEASURE WATER1. Verify system design efficiency

A. Distribution uniformityB. Matched sprinkler precipitation ratesC. Sprinkler zone make-up by:

A. Plant materials (crop coefficients)B. SlopeC. ExposureD. Soil type

D. Observe Actual Precipitation Rate


REASON #2 TO MEASURE WATER2. Create a Water Budget and Balance Supply

with Demand

LWA ≥ LWRYou cannot Balance unless you measure


REASON #3 TO MEASURE WATER3. Document what you have done

A. Keep detailed records of water usage, ET or temperature information, etc. by day, month, season, year

B. Defend your water usage with dataC. Market your skill as a water managerD. Promote your organization as a good citizen and

good steward of the environment.


REASON #4 TO MEASURE WATER

4. Detect Leaks and Prevent Waste


REASON #5 TO MEASURE WATER

Comply with the new Cal. MWELO


Fundamentals


Flow Sensor Parts


Water flowing through the pipe turns the

impeller

Electronics in the insert count the blades as they go by the detector

The output is a digital pulse proportional to the speed of rotation

Formula converts the signal into a flow rate using conversion factors (K and Offset, PPG)


Designed to measure a range of water qualities

Rate of Flow measuring device

Broad range of flow Negligible pressure

loss Fast Signal format

Flow Sensor


Meter vs. SensorWater Meter

Designed to measure domestic (potable) water

Totalizer Clean water only Limited range of

flows High pressure loss Slow signal format


Flow Sensor Insert


Alternative Mounting Options


Alternative Mounting Options




19

Flow sensor wiring





Why is CST a better mousetrap? Comparison with other impeller sensors

2. 1” Sensor ConstructionCST has a 1 inch PVC Sensor in the FSI seriesDI has only a threaded brass unit.

Creative Sensor Technology, Inc. 24

3. Sensor Assembly

The CST sensor insert is held into the mounting tee with a larger diameter, ACME threaded retaining nut making disassembly and assembly quick and easy, particularly in underground valve boxes.

The DI sensor insert is held in the mounting tee with a pin and split ring. The insert must be aligned and inserted to the correct depth in order to push the pin horizontally through the housing. This can be awkward and difficult in the small valve box.



4. Saddle type sensors

◦ Available in 3 and 4 inch◦ Easier to install on

larger pipe sizes◦ Complete with saddle◦ Offers same wide range

of flows

5. Electrical Protection The CST sensor electronics have been designed

with protection against reverse wiring, overvoltage and over current.

6. Watertight Integrity The CST sensor housing and wiring has been

designed to protect the electronics from moisture, improving on the design flaw of the DI sensor.


CST Sensor Advantages Better low flow detection Easier to install/service with jar top Better electronic protection Higher pressure rating Virtually no friction loss Lower cost



Why are we better?

Comparison with combination master valve/meters (Hydrometer


Hydrometer







Installation






To Summarize-Add flow measurement to:1. Verify that your installed system meets the

design goals of efficiency and functionality2. Verify water application rates and balance

water use with available water supply3. Document and record water usage and

savings4. Prevent water loss or site damage by

continually monitoring flow

Questions?

Documents

By Norman Bartlett Creative Sensor Technology 1. Irrigator’s View of Landscape Irrigation “ We are beautifying the world” Public’s View “You are wasting