ASTTBC Tech Exam cheat sheet

SI base units: length metre (m), mass kilogram (kg), time second (s), electric current ampere (A), thermodynamic temperature kelvin (K), amount of substance mole (mol), luminous intensity candela (cd).

Unit conversion chain: multiply by ratios equal to one; convert to base SI units first, then to the target unit, to avoid inverted factors.

Derived units: force newton (N = kg·m/s²), pressure pascal (Pa = N/m²), energy joule (J = N·m), power watt (W = J/s), frequency hertz (Hz = 1/s).

Significant figures: the result of multiplication or division carries the same count as the least precise input; addition and subtraction keep the least number of decimal places.

Measurement error: absolute error = measured − true; relative error = absolute error ÷ true value; percent error = relative error × 100%.

Linear tolerance stack-up: total variation equals the sum of individual tolerances for worst-case assembly; root-sum-square applies when independent random errors combine.

Calibration traceability runs unbroken to a national or international standard; a calibration certificate states the measured value, uncertainty, and coverage factor k.

Statistics: mean = sum ÷ n; standard deviation of a sample uses n − 1 in the denominator; expanded uncertainty U = k·u with k = 2 giving roughly 95% coverage.

Hold public safety, health, and welfare paramount; where a professional duty and an employer instruction conflict, the public interest governs.

Sign and seal only work you personally prepared or directly supervised; sealing another person's unreviewed work is misconduct.

Report known errors or unsafe conditions to the responsible party in writing; if unresolved, escalate to the regulator rather than remain silent.

Conflicts of interest must be disclosed in writing before the affected decision; disclosure does not remove the duty to avoid bias.

Confidentiality covers client data, drawings, and reports; it ends where law, a court order, or public safety requires disclosure.

Accept only assignments within your competence; obtain specialist review or decline when the scope exceeds your training and experience.

Give credit for others' contributions and keep verifiable records of calculations, tests, and decisions for the required retention period.

Bribery, falsified test data, and misleading credentials are reportable offences; self-report promptly if you discover your own error.

A statute sets the legal duty; regulations made under it define the technical requirements; codes and standards are incorporated by reference and gain legal force.

Workers' compensation legislation is no-fault: injured workers receive statutory benefits and generally surrender the right to sue the employer.

Occupational health and safety law imposes a general duty on employers to provide a safe workplace and on workers to follow safe procedures and report hazards.

Contracts contain offer, acceptance, and consideration; a professional's standard of care is that of a reasonably competent practitioner in the same field.

Negligence requires four elements: a duty of care, a breach of that duty, causation, and actual damages.

Limitation periods cap the time to sue; they differ for contract and tort claims and may run from discovery of the defect.

Regulated title and scope of practice are defined in the governing act; using a reserved title or practising outside scope is an offence.

Professional liability insurance covers errors and omissions, not deliberate acts; keep records for the period the policy and statute require.

Lockout/tagout: isolate every energy source, dissipate stored energy, verify zero energy, and apply a personal lock before work begins.

Electrical safety: treat circuits as live until tested with a rated meter; test before touch, and use the category-rated instrument for the voltage present.

Personal protective equipment is the last line of defence; the hierarchy of controls runs elimination, substitution, engineering controls, administrative controls, then PPE.

Ladder rule: maintain a 4:1 slope for a leaning ladder and keep three points of contact; secure the top and extend it about 1 m above the landing.

Confined spaces require hazard assessment, atmospheric testing for oxygen and contaminants, ventilation, an attendant, and a rescue plan before entry.

Guarding: fixed guards protect against rotating parts; interlocks must prevent operation while the guard is open and must not be easily bypassed.

Incident reporting: preserve the scene, give first aid, report to the regulator within the statutory time, and record findings for corrective action.

Risk assessment: risk = likelihood × severity; controls are chosen to reduce risk to as low as reasonably practicable, and residual risk is documented.