CWT Practice Test

The Certified Weighing Technician (CWT) exam from the International Society of Weighing and Measurement (ISWM) is for people who work on weighing equipment and want a recognised credential. This page has free practice sets grouped by topic and worked answers to sample questions. It also sums up the verified exam rules: a proctored paper-and-pencil test of approximately 100 multiple-choice questions.

CWT Exam at a Glance

What changed for CWT in 2026

• Oct 27, 2026: Number of questions changed to Approximately 100 multiple-choice questions (previously About 100 multiple-choice questions).^[1]
• Oct 27, 2026: Retake policy changed to 2 retakes without paying additional application fees; reapply after 3 failures (previously 2 retakes without a new application; reapply after 3 failures).^[2]
• Oct 27, 2026: Registration deadline changed to At least 30 days prior to the testing date (previously At least 30 days before the test date).^[2]
• Oct 27, 2026: Passing score changed to Criterion-referenced standard (no curve) (previously Criterion-referenced standard, no curve).^[2]
• Oct 27, 2026: Score release changed to Mailed approximately 6 to 8 weeks after administration (previously Mailed about 6–8 weeks after the exam).^[2]
• Oct 27, 2026: Renewal changed to Every 5 years via ISWM continuing education or retesting (previously Every 5 years by ISWM continuing education or by retesting).^[2]
• Oct 27, 2026: Delivery changed to Proctored paper-and-pencil exam at designated test sites (previously Paper and pencil exam at a proctored test site).^[2]

What the CWT is and how it works

According to International Society of Weighing and Measurement, “The CWT examination will consist of approximately 100 multiple-choice questions (MCQ).”^[1]

The CWT credential from ISWM shows that a technician knows how to work on weighing equipment to a set standard. ISWM publishes the rules on its testing details page. If anything here differs from that page, follow ISWM.

Delivery. The exam is a proctored paper-and-pencil test given at designated test sites. Arrive on time, because proctors will not admit candidates who arrive after the examination instructions have been read.

Format and scoring. Expect approximately 100 multiple-choice questions. The passing level is criterion referenced. That means the Examination Committee sets a fixed standard of knowledge, and you are not graded on a curve against other candidates. ISWM mails written results approximately 6 to 8 weeks after the exam.

Applying and retakes. Your application must be fully completed and submitted at least 30 days before the testing date. If you do not pass, you can retake the exam 2 times without paying the application fee again. Test fees still apply to each attempt. After 3 failures you must reapply.

Renewal. Certification is valid for 5 years. You renew through ISWM authorized continuing education, or by retaking the exam or portfolio analysis. This page does not cover eligibility requirements, fee amounts or test-site dates, so check those directly with ISWM.

Worked examples: how to reason through CWT questions

These are practice questions written for this site, not questions from the real exam. Each explanation shows why the right answer is right and why the others are wrong.

Example 1

Question: A weights-and-measures inspector applies an official seal to a scale after inspection. What does this seal signify?

1. The device has passed inspection and is legally approved for commercial use
2. The device has been permanently retired from service
3. The device is approved for laboratory use only
4. The device requires quarterly recalibration

Answer: A. The device has passed inspection and is legally approved for commercial use

Explanation:

A is right. An inspector applies an official seal after finding the device within tolerance. The seal means the device is approved for commercial transactions, so buyers and sellers can rely on its readings.

• B is wrong: retired devices are taken out of service or marked as rejected. They are not sealed as approved.
• C is wrong: the seal approves commercial, legal-for-trade use. It does not mean laboratory-only status.
• D is wrong: a seal does not set a recalibration schedule. It records that the device passed and that its adjustable parts have not been disturbed since.

Rule to remember: a seal is evidence of an approved device that nobody has tampered with. If the seal is broken, the device's approved status is in doubt until it is inspected or properly re-sealed.

Example 2

Question: How do environmental factors affect measurement accuracy?

1. No effect
2. Cause deviations
3. Always improve
4. Only affect speed

Answer: B. Cause deviations

Explanation:

B is right. Temperature, humidity, air pressure, air currents and vibration can all pull a scale's reading away from the true value. Temperature changes can affect load cells and other components, and drafts and vibration push on the platform. Moisture can affect both the electronics and the load itself.

• A is wrong: no real scale is fully isolated from its surroundings.
• C is wrong: the environment does not reliably improve readings. At best, a controlled environment keeps errors small.
• D is wrong: environmental effects change the weight value itself, not only how quickly the display settles.

Rule to remember: when a scale drifts or gives inconsistent results, check the environment before assuming the device is faulty. Test the scale under the conditions where it is actually used.

Example 3

Question: When must a service technician re-seal a weighing device after performing repairs?

1. Only if the customer requests it
2. After any adjustment or repair that could affect metrological performance
3. Only after replacing load cells
4. Sealing is optional if the technician documents the repair

Answer: B. After any adjustment or repair that could affect metrological performance

Explanation:

B is right. Metrological performance means how accurately the device weighs. Any adjustment or repair that could affect it means the device must be re-sealed, so its approved status stays intact.

• A is wrong: sealing commercial devices is a legal requirement, not a customer preference.
• C is wrong: load cells are only part of the picture. Changes to calibration settings, indicators or any other part that affects accuracy count too.
• D is wrong: documenting your work is good practice, but it does not replace the seal.

Rule to remember: if your work could change what the scale reads, restore the seal. Local weights-and-measures rules may also require you to report the repair.

How to use these practice tests

Start with ISWM's official CWT page and testing details page. Find the next test date at a site near you and plan backward from it. Your application must be complete and submitted at least 30 days before that date, so treat that as your first deadline.

Next, find your starting point. Work through CWT Fundamentals & Core Concepts without notes and write down which topics you miss. Then use the topic sets to fill the gaps, giving the most time to your weakest areas:

• Accuracy and tolerances: Measurement Standards & Accuracy, then Weighing Equipment Operation & Calibration.
• Field work: Installation & Verification and Troubleshooting & Maintenance.
• Rules and records: Legal Metrology & Regulatory Compliance and Data Recording & Reporting.
• Safety and conduct: Safety Procedures & Compliance, Safety & Risk Management, Standards & Best Practices and Professional Ethics & Conduct.

For every question you miss, read the explanation and write the general rule in your own words. Wait a while before retaking a set, so you are recalling answers rather than recognising them. Near test day, take the full practice test in exam-like conditions: a quiet room, no phone, in one sitting. The real exam is paper-and-pencil with approximately 100 questions.

Sources & last verified

1. International Society of Weighing and Measurement — number of questions (official source). “The CWT examination will consist of approximately 100 multiple-choice questions (MCQ).” Verified Oct 27, 2026 · source checked Oct 24, 2026.
2. International Society of Weighing and Measurement — passing score, retake policy, validity, renewal (official source). “The passing level is a standard of knowledge set by a criterion referenced methodology (similar to setting par in golf), using the combined judgments of…” Verified Oct 27, 2026 · source checked Oct 24, 2026.

How we verify: editorial & fact-checking policy. Report an error: contact us.