Unit 5 — Calibration and Verification

TM-GEAR-019 — Open Handout TM Chapters: Chapter 6, Chapter 7 ELOs: Calibrate the VARIABLE CAPACITORS — AIR, MOTORIZED, AND STACK-ON FLAT-PLATE; verify performance against acceptance criteria; complete calibration log Estimated time: 45 minutes (actual lab work required)

Step 1: Read the TM

Open TM-GEAR-019. Read Chapter 6 — Calibration and Chapter 7 — Verification and Acceptance completely.

Then come back here.

Chapter 6 — Calibration Content

  1. Motorized cap: move the capacitor to 10 equally-spaced pot positions. Measure capacitance at each position with an LCR meter or NanoVNA (use the impedance measurement mode at a known frequency). Store the (ADC_value, pF) table in ESP32 NVS.
  2. Stack-on caps: measure each unit individually with an LCR meter at 100 kHz. Label each unit with its measured capacitance. Build a combination table: n units in parallel = n × C_unit.

Chapter 7 — Verification Content

  1. Motorized cap positioning: command each of 5 target capacitances; measure actual capacitance; error must be <5% of target.
  2. Limit switch test: command travel past the end limits; controller must stop at the limit switches without mechanical damage to the capacitor.
  3. Stack-on units: each unit must measure within 20% of its labeled value (LCR meter verification; flat-plate caps have significant tolerance).
  4. HV rating: apply the rated voltage across the capacitor at maximum capacitance setting and hold for 10 seconds. No arc-over or increase in leakage current.
  5. Log: date, cap type, calibration table (10 points for motorized), stack-on unit values, positioning accuracy, operator.

Calibration vs. Verification — Distinction

Calibration (Chapter 6): active adjustments to bring the component within specification. You are permitted to adjust, tweak, and repeat until the criterion is met.

Verification (Chapter 7): independent confirmation that the calibration succeeded. No adjustments are permitted during verification. If a verification check fails, you return to Chapter 6, not to Chapter 7.

Acceptance Criterion

A criterion found in Chapter 6: 100 kHz. Confirm the exact criterion in the TM.

Write the exact criterion from the TM here before you start the lab:

Lab Checklist

Work through each item in sequence. Do not skip steps.

  • [ ] All required equipment gathered and ready
  • [ ] Equipment warmed up per TM requirements
  • [ ] All Chapter 4 setup steps verified complete
  • [ ] Chapter 6 calibration performed (all steps)
  • [ ] Calibration criterion met (recorded below)
  • [ ] Chapter 7 verification performed (all steps, no adjustments)
  • [ ] All verification criteria passed
  • [ ] Calibration log entry completed

Calibration Log Entry

  • [ ] Date
  • [ ] Equipment used
  • [ ] Measurements taken
  • [ ] Results vs. criteria
  • [ ] Operator name

Record your results:

Item Measured Value Acceptance Criterion Pass/Fail
(from Ch 7)
(from Ch 7)
(from Ch 7)

Self-Check Questions

SC5-1. What is the acceptance criterion for this calibration (from Chapter 7)?

SC5-2. During verification, one reading fails. What is the correct action per the TM?

SC5-3. List the items required in a calibration log entry per Chapter 7.

SC5-4. What is the difference between calibration and verification in this context?

SC5-5. If the component passes all Chapter 7 checks, what does that tell you about its current state?

Answer Key

SC5-1. See Chapter 7. The criterion is stated as a specific value with units.

SC5-2. Stop verification. Return to Chapter 6 and re-calibrate. Diagnose the cause before re-adjusting.

SC5-3. See Chapter 7, last numbered step. The log items are listed there.

SC5-4. Calibration allows adjustments; verification does not. Verification is independent confirmation.

SC5-5. It tells you the component is performing within its specified parameters at this time. It does not tell you how long it will remain in calibration — periodic re-verification is required.

Checkpoint

You are ready for the final assessment when you can: - [ ] State the acceptance criterion from memory - [ ] State the difference between calibration and verification - [ ] State the required log items from memory

→ Proceed to Final Assessment