CST Study Guide 2026

Everything you need to pass the CST exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.

📋 CST Exam Format at a Glance

100
Questions
120 min
Time Limit
70%
Passing Score

📚 CST Topics to Study (69)

✍️ Sample CST Questions & Answers

1. Electromagnetic compatibility (EMC) shielding on a digital scale cable is important primarily because:
It protects the low-level mV load cell signal from radio frequency and electromagnetic interference

Load cell output signals are very small (in the millivolt range), making them highly susceptible to RFI/EMI noise that shielding helps block.

2. NIST HB 44 requires that the 'test weights' used for field inspection of commercial scales must:
Be certified to a tolerance within one-third of the applicable device tolerance

Field standards (test weights) used in official inspections must have errors no greater than one-third of the tolerance of the device being tested, per HB 44 requirements.

3. What is the federal maximum gross vehicle weight (GVW) limit for vehicles operating on U.S. interstate highways?
80,000 lbs

Federal law limits gross vehicle weight to 80,000 lbs on interstate highways under the Federal Bridge Formula.

4. What mechanical feature protects load cells from permanent damage caused by sudden shock loading or overload impacts?
Mechanical overload stops or bumpers that limit platform travel and deflection

Mechanical overload stops physically limit how far the scale platform can deflect under load, preventing the load cells from experiencing forces beyond their safe overload rating.

5. An automatic bulk weighing system fills bags of grain sold by weight. Which NIST HB 44 section and key accuracy consideration applies?
Section 2.22 – Automatic Weighing Systems; batch accuracy over multiple consecutive weighments

Automatic bulk weighing systems are covered under NIST HB 44 Section 2.22, which specifies accuracy requirements evaluated across multiple consecutive automatic weighments.

6. When replacing a sealed load cell, a technician must apply sealant around the cable entry point. What is the primary purpose of this step?
To prevent moisture from wicking into the load cell along the cable

Sealing the cable entry prevents moisture from entering the load cell via capillary action along the cable, which would degrade insulation resistance and cause signal errors.

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Your CST Study Path
1. Learn with Flashcards → 2. Drill Practice Tests → 3. Take the Full Exam Simulation
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