Interpreting Diagrams free demo
In TECH · about 4 minutes · Choose an answer
About the Interpreting Diagrams section
Interpreting Diagrams is one of the four tests in EEI's TECH battery. The brochure says it measures the ability to use symbols and codes to locate objects on a map or diagram and to determine the object's status — and that is all it says. No count, no time limit and no sample you can reuse are published.
Our practice builds exactly those two skills, locating and determining status, on four kinds of original diagram: an equipment map on a lettered grid with a symbol key; a two-supply switching one-line where you trace which loads are energized; a two-tank valve diagram, where an open valve passes water; and a floor plan of equipment tags decoded with a code key that changes from plan to plan, so you have to read the key every time.
Every diagram is generated, and every answer is worked out again by a separate checking script from the same diagram you see, which also confirms that exactly one option is right. Our timed pace, 24 questions in 20 minutes, is our own choice, because EEI does not publish one.
Tips from practice
- Read the key first, every time. Our tag plans deliberately change the codes, and a real test can too.
- Name grid squares column first, then row: C4 is column C, row 4.
- On a one-line, trace from the load back to a source and stop at the first open switch — or, on a valve diagram, the first closed valve.
- Watch the difference between a switch and a valve: a CLOSED switch lets current through, but an OPEN valve lets water through.
Common questions
- What is on the real Interpreting Diagrams test?
- EEI only publishes a one-line description: using symbols and codes to locate objects on a map or diagram and to determine an object's status. Our diagrams are original practice for that description, not copies of real items.
- Do I need electrical knowledge?
- No. Everything you need is in the diagram and its key, including what each symbol means and how current or water gets through. Our explanations spell out the path every time.
This demo is independent practice, written from publicly published descriptions of the section. It is not affiliated with or endorsed by the Edison Electric Institute or any utility, and it is not identical to any real test.