CWT Safety Procedures & Compliance 4 — Questions and Answers
Question 1: Which type of test weight class is required for testing Class III commercial scales with a capacity of 500 lb?
- Class F test weights
- Class OIML M1 weights only
- Weights meeting NIST Class F or better tolerances (Correct answer)
- Any calibrated weights regardless of class
Correct answer: Weights meeting NIST Class F or better tolerances
NIST Handbook 105-1 specifies that test weights used for Class III device verification must meet Class F tolerance requirements or better.
Question 2: When a CWT encounters a scale that displays weight in a non-approved unit of measure for a given commodity transaction, the correct action is to:
- Convert the reading mentally and certify the scale
- Approve the device if the conversion factor is posted nearby
- Reject certification because unapproved units violate NIST HB 44 requirements (Correct answer)
- Issue a conditional approval pending unit change within 60 days
Correct answer: Reject certification because unapproved units violate NIST HB 44 requirements
NIST HB 44 specifies which units of measure are approved for each type of commercial transaction; non-approved units are grounds for rejection.
Question 3: During a calibration of a crane scale at height, the technician should ensure which safety measure is in place?
- The crane operator leaves the cab during calibration
- Anti-fall protection is worn and the swing radius below is barricaded (Correct answer)
- The scale is calibrated only when the crane is at minimum height
- Verbal communication only, with no hand signals
Correct answer: Anti-fall protection is worn and the swing radius below is barricaded
Working at elevation requires fall protection for the technician and barricading the swing radius below to protect ground-level personnel from falling objects.
Question 4: What is the significance of the 'maintenance tolerance' versus the 'acceptance tolerance' in NIST HB 44?
- They are identical; both terms refer to the same tolerance
- Maintenance tolerance is more lenient and applies to devices already in service (Correct answer)
- Acceptance tolerance is more lenient and applies to devices in service
- Maintenance tolerance applies only to Class I analytical balances
Correct answer: Maintenance tolerance is more lenient and applies to devices already in service
Maintenance tolerances are twice as lenient as acceptance tolerances and apply to devices already in commercial service, while acceptance tolerances apply to new or repaired devices.
Question 5: A CWT is testing a scale in a flour mill where combustible dust is present. Which safety requirement applies to all electrical equipment brought in?
- Standard commercial-grade tools are acceptable with dust covers
- Equipment must be rated for use in Class II, Division 1 or 2 hazardous locations (Correct answer)
- Only battery-powered tools under 12V are permitted
- Dust hazards apply only to open flames, not electrical equipment
Correct answer: Equipment must be rated for use in Class II, Division 1 or 2 hazardous locations
Combustible dust environments are classified as Class II hazardous locations under the NEC, requiring explosion-proof or dust-ignition-proof rated equipment.
Question 6: Which procedure must a CWT follow before applying an 'Approved' seal to a device?
- Obtain verbal permission from the device owner
- Verify the device passes all applicable tests under NIST HB 44 and complete required documentation (Correct answer)
- Confirm the device has a valid manufacturer's warranty
- Check that the device is less than 10 years old
Correct answer: Verify the device passes all applicable tests under NIST HB 44 and complete required documentation
Certification seals may only be applied after the device has passed all required tests and all documentation has been completed per regulatory requirements.
Question 7: A technician is calibrating a scale in a meat packing plant where floors may be slippery with animal fat. The most appropriate footwear is:
- Standard leather work boots
- Slip-resistant safety footwear with waterproof construction (Correct answer)
- Athletic shoes for comfort during long shifts
- Any closed-toe shoe is sufficient per OSHA
Correct answer: Slip-resistant safety footwear with waterproof construction
Slip-resistant, waterproof safety footwear is required in wet and greasy food processing environments to prevent slip-and-fall injuries.
CWT Safety Procedures & Compliance 4
Which type of test weight class is required for testing Class III commercial scales with a capacity of 500 lb?