7 min read
How to run a catch-can test
Step-by-step catch-can audit procedure: how many cans to set, where to place them, how long to run the zone, and how to turn the readings into DU, CU, and precipitation rate.
Guides · 6 articles · free
Irrigation audit guides
The audit tool computes the numbers. These guides cover what a calculator cannot: how to set the cans, what DU and CU actually measure, why mixed nozzles wreck uniformity, how to split runtimes so water soaks in, and how to price the savings off a real water bill.
6 min read
DU vs CU: understanding irrigation uniformity
What low-quarter distribution uniformity (DU) and Christiansen's coefficient of uniformity (CU) actually measure, how each is computed from catch-can data, and which one to schedule from.
6 min read
Matched precipitation rate: why mixed nozzles wreck uniformity
What matched precipitation means, how mixing full-circle and part-circle heads or different nozzle families on one zone creates wet and dry areas, and how an audit exposes the mismatch.
6 min read
Cycle-soak scheduling: stop paying for runoff
How to split a long runtime into short cycles with soak intervals so water infiltrates instead of running off, using soil intake rate and measured precipitation rate to size each cycle.
6 min read
Reading a water bill for irrigation savings
How to translate audit gallons into billed dollars: units, tiered rates, sewer charges, dedicated irrigation meters, and why savings estimates are estimates rather than guarantees.
5 min read
Converting mL catch readings to inches of depth
How to turn graduated-cylinder millilitre readings into depth: measure the catch device's throat area, divide volume by area, and avoid the unit traps that corrupt a test.
Where to start
New to catch-can auditing? Read how to run a catch-can test first, then feed your readings into the audit tool. If you already have a DU number and want to know whether it is any good, the DU target tables put it in context.