Year 3 Exam Study Guide — master what the exam actually tests, concept by concept.
Electrical calculations are the backbone of proper installation — undersized wire causes fires; oversized breakers don't protect equipment. Every formula on this exam has a practical application: sizing conductors, calculating demand loads, determining motor current, or checking voltage drop. Know the formula, understand the variables, and practice the math.
Cascade: outer loop (slow process) controls inner loop (fast process). Inner response faster, outer tracks setpoint better. On the job, a solid grasp of this concept means faster decisions, fewer errors, and work that passes inspection the first time.
Ratio control: output setpoint = input × constant (ratio). Maintains feed/fuel ratio automatically despite flow variations. Memorize this formula and practise substituting values — exam questions often give you three variables and ask you to solve for the fourth.
output setpoint = input × constant (ratio)
Feedforward: reacts to disturbance directly (e.g., load increase) before temperature drops. Faster correction than feedback alone. On the job, a solid grasp of this concept means faster decisions, fewer errors, and work that passes inspection the first time.
Equal-percentage valve: proportional gain increases with opening. Installed characteristic depends on system pressure ratio. Sizing critical. On the job, a solid grasp of this concept means faster decisions, fewer errors, and work that passes inspection the first time.
Choked flow: velocity reaches sonic speed; further downstream pressure drop doesn't increase flow. Typically indicates oversized valve. On the job, a solid grasp of this concept means faster decisions, fewer errors, and work that passes inspection the first time.
GC analysis: sample injected, compounds separated by boiling point, detected. Peak identification via retention time; quantified by area. On the job, a solid grasp of this concept means faster decisions, fewer errors, and work that passes inspection the first time.
Every conductor, conduit, fitting, device, and panel component has specific properties that determine where and how it can be used. Knowing the right material for the application — conductor type, conduit fill, box sizing — is exactly what the exam tests here.
Cavitation: low-pressure bubbles form and collapse. Sound like marbles in pipes; erosion of valve surfaces. Right-size valve to avoid. On the job, a solid grasp of this concept means faster decisions, fewer errors, and work that passes inspection the first time.
pH sensor: two-point calibration (buffers), electrode stored in solution (prevent drying). Sensitive to contamination; maintenance critical. On the job, a solid grasp of this concept means faster decisions, fewer errors, and work that passes inspection the first time.
NDIR analyzer: detects molecules with IR absorption bands (CO2, CO, HC). O2 non-IR, requires thermal/electrochemical sensor. On the job, a solid grasp of this concept means faster decisions, fewer errors, and work that passes inspection the first time.
Instrument heat trace: electrical cable on line, controlled temperature. Prevents sample condensation (water blocks or biases readings). On the job, a solid grasp of this concept means faster decisions, fewer errors, and work that passes inspection the first time.
All 10 exam concepts from this guide — test your recall before you sit the exam.