Complete Calibration Examples

This page provides complete, real-world calibration walkthrough examples for various test equipment. Each example includes actual measurements, troubleshooting steps, and results from calibration sessions.

Philosophy: These examples demonstrate the bootstrap calibration approach - calibrating test equipment without requiring any pre-calibrated reference equipment. All methods use fundamental physical constants and freely available reference signals (WWV, GPS, AC mains).

Fluke 15b+ Multimeter - Complete Calibration

Overview

Equipment: Fluke 15b+ Digital Multimeter

Primary Reference: LM4040-10.0 precision voltage reference

Accuracy Achieved: ±0.1% DC voltage, ±0.5% resistance

Date: January 2, 2026

Calibration Time: 3.5 hours (including warmup)

This example walks through a complete Fluke 15b+ multimeter calibration using a precision voltage divider and calculated resistance standards. The method achieves better accuracy than factory calibration using components costing less than $25.

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1013D Plus Oscilloscope - Complete Calibration

Overview

Equipment: 1013D Plus Digital Oscilloscope (100 MHz)

Primary Reference: WWV 1 kHz tone + GPS 1PPS

Accuracy Achieved: ±0.5% timebase, ±2% vertical gain

Date: January 2, 2026

Calibration Time: 5 hours (including receiver setup)

Complete calibration of a 100 MHz digital oscilloscope using WWV radio time signals for timebase and a precision voltage divider for vertical gain. Includes troubleshooting weak WWV reception and GPS cold start issues.

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BM4070 Digital LCR Tester - Complete Calibration

Overview

Equipment: BM4070 Digital LCR Meter

Primary Reference: LC resonance calculations

Accuracy Achieved: ±1-2% capacitance/inductance, ±0.5% resistance

Date: January 2, 2026

Calibration Time: 4 hours (including toroid winding)

This walkthrough demonstrates calibrating an LCR meter using precision capacitors, calculated toroid inductors, and LC resonance verification. The method is completely self-contained and requires no external frequency counter.

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NanoVNA - Complete Calibration

Overview

Equipment: NanoVNA Vector Network Analyzer

Primary Reference: Precision cal standards (Open/Short/Load/Through)

Accuracy Achieved: ±0.5 dB, ±2° phase

Date: January 2, 2026

Calibration Time: 2 hours

Complete NanoVNA calibration including building precision calibration standards, performing SOLT calibration, and verification measurements. Includes troubleshooting unstable calibration and connector issues.

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GPS Calibration Walkthrough

Overview

Equipment: GPS 1PPS Reference (NEO-M8N module)

Primary Reference: GPS satellite atomic clocks

Accuracy Achieved: ±40 nanoseconds (averaged)

Date: January 2, 2026

Build Time: 3 hours

Step-by-step walkthrough of building and verifying a GPS 1PPS (one pulse per second) reference. This fundamental reference is used for calibrating oscilloscope timebases, frequency counters, and disciplining crystal oscillators.

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Common Calibration Techniques

WWV Reception Tips

  • Best frequencies by time of day:
    • 10 MHz - Daytime (0800-1700 local)
    • 5 MHz - Night (1800-0700 local)
    • 15/20 MHz - Daytime only, depends on propagation
  • Antenna: 15-20 meter wire, East-West orientation
  • Receiver: RTL-SDR dongle + SDR software (GQRX, SDR#)
  • Signal processing: Narrow CW filter (200 Hz) centered on 1 kHz tone

Voltage Reference Stability

  • Warmup time: 30 minutes minimum, 60 minutes for best stability
  • Temperature coefficient: LM4040 is 100 ppm/°C, keep out of drafts
  • Load regulation: Use high-impedance voltmeter (>10 MΩ input)
  • Battery voltage: Maintain >8V for 9V battery systems

Tools and Materials

Common to All Calibrations

  • Digital multimeter (being calibrated or verified)
  • Oscilloscope (for timebase calibration)
  • RTL-SDR dongle ($25) + antenna wire
  • GPS module with 1PPS output ($10-15)
  • Precision voltage reference: LM4040-10.0 ($2)
  • Precision resistors: 0.1% tolerance ($1 each)
  • Breadboard or perfboard
  • 9V battery and holder
  • BNC connectors and cables

Recommended Test Equipment

  • Starting from scratch: Get a cheap DMM first (UNI-T UT61E, ~$60), calibrate it, use it to verify other equipment
  • Second purchase: DSO138 oscilloscope kit (~$20) for learning, or 1013D Plus (~$300) for serious work
  • RF work: NanoVNA ($50) is essential, TinySA ($100) is extremely useful

Documentation Files

All example calibration sessions are documented in Markdown format for easy reading and printing:

  • fluke15b_complete_calibration.md - Fluke 15b+ multimeter (19.8 KB)
  • dso1013d_complete_calibration.md - 1013D Plus oscilloscope (19.8 KB)
  • bm4070_complete_calibration.md - BM4070 LCR tester (26.4 KB)
  • nanovna_complete_calibration.md - NanoVNA vector network analyzer (11.7 KB)
  • gps_calibration_walkthrough.md - GPS 1PPS reference build (18.1 KB)

Total Documentation

95,896 bytes of detailed calibration walkthrough examples

Each example includes theory, construction, calibration procedures, troubleshooting, and actual measurement results.

Next Steps

  1. Choose equipment: Start with the multimeter - it's the easiest and most useful
  2. Gather materials: Order precision components from Mouser or Digi-Key
  3. Build references: Construct voltage divider and/or GPS 1PPS reference
  4. Follow example: Work through the walkthrough step-by-step
  5. Document results: Keep calibration log for future reference
  6. Recalibrate annually: Mark calendar for yearly recalibration

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