Practice Test Geeks(CST) Certified Scale Technicians Practice Test
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Repeatability & Linearity Testing Flashcards

7 cards from real CST practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Repeatability & Linearity Testing flashcards as text

  1. According to NIST HB 44, what is the maximum permissible error (MPE) for repeatability for a Class III scale with a scale division of 0.1 lb?

    Answer: 0.1 lb (1d)

    For Class III scales, the MPE for repeatability is one scale division (1d), meaning all repeated readings must agree within 1d.

  2. When testing a crane scale for linearity, the technician should:

    Answer: Apply loads by hanging certified test weights from the hook

    Crane scales are designed to operate in tension; linearity tests must apply loads in the same manner (hanging weights) to simulate actual use conditions.

  3. A scale technician records these 5 repeatability readings at 50 lb: 50.1, 50.0, 50.1, 50.2, 50.0. The repeatability error is:

    Answer: 0.2 lb

    Repeatability error equals the difference between the highest and lowest readings: 50.2 − 50.0 = 0.2 lb.

  4. For linearity testing, NIST HB 44 specifies that test loads should be placed at a minimum of how many points across the scale's range?

    Answer: 5 points approximately equally spaced

    NIST HB 44 requires testing at a minimum of approximately five equally spaced load points to adequately characterize linearity across the full range.

  5. A load cell's rated output is 2 mV/V. During linearity testing, the output at half capacity measures 0.95 mV/V instead of 1.0 mV/V. This deviation is best described as:

    Answer: Nonlinearity error at mid-range

    An output that deviates from the ideal linear response at mid-range (0.95 vs. 1.0 mV/V) is a classic nonlinearity error in the load cell.

  6. When should a repeatability test be re-run after the scale is adjusted?

    Answer: After every adjustment to verify the correction was effective

    Repeatability testing should be performed after any adjustment to verify that the adjustment resolved the issue and did not introduce new problems.

  7. A hopper scale used to fill bags shows different weights for the same batch depending on the fill rate. This symptom is most likely caused by:

    Answer: Dynamic loading effects causing repeatability errors

    Dynamic effects during fast filling (impact, vibration, inertia) can cause the scale to record different readings for the same static load, appearing as repeatability failure.