Time-Frequency Calibration
Since ancient times, humans have used stable natural cycles for timekeeping—years from the solar cycle, months from the lunar cycle, and days from Earth's rotation. Precision timekeeping evolved from sundials and water clocks to quartz oscillators, paralleling civilization's progress from nomadic to industrial societies. Precision instruments rely on internal frequency oscillation, with cesium atomic clocks being the standard for defining a second due to their exceptional stability and accuracy.
Calibration systems for time and frequency instruments are crucial. Key components include:
International Traceability: National time and frequency standards labs trace back to the International Bureau of Weights and Measures (BIPM) standards, ensuring domestic calibration traceability.
Measurement Item Development: Time correction involves time scaling and interval measurements; frequency correction ranges from 1 Hz to several tens of GHz.
Collaboration with Standards Bodies: Supporting labs in establishing secondary standards to strengthen the national time and frequency traceability system.
Oscillators are classified into three levels based on performance, from atomic frequency standards to standard quartz oscillators. Our lab has developed remote time and frequency calibration technology, using satellite common-view methods for calibration without physical relocation, ensuring both impartiality and confidentiality in our services.
Laboratory Calibration Capabilities
| Measurement Calibration | Range | Equipment/Method | Best Calibration Capability | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| Time | -1000 s ~ 1000 s | SR620 Time Scaling Measurement | 8 ns (Traceable to UTC) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 1pps | SR620 Time Interval Measurement | 1 ns | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| -0.5 s ~ 0.5 s | Portable Cesium Clock Method (On-site Calibration) | 3 ns (Traceable to National Time Standard/Travel within 3 hours) 6 ns (Traceable to National Time Standard/Travel 3 to 30 hours) 10 ns (Traceable to UTC/Travel within 30 hours) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Frequency | 1 Hz ~ 300 MHz | SR620 Direct Frequency Measurement | 3.0E-12 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 5, 10 MHz | Remote Frequency Calibration System | 2.0E-12 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 1, 5, 10 MHz | SR620 Phase Comparison | 3.0E-13 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 5, 10 MHz | A7-MXU Phase Comparison | 5.0E-14 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 300 MHz ~ 40 GHz | Microwave Frequency Measurement System | 6.0E-12 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 1 Hz ~ 300 MHz | SR620 Direct Frequency Measurement | 3.0E-12 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Laboratory Calibration Fee Schedule
| Systems | Items for Calibration | Fee Standard | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| Time Measurement | 1. Cesium or Rubidium Time Standards 2. GPS Receivers 3. Second-Level Items (Temperature-Controlled Quartz Oscillators) 4. Third-Level Items (Below Temperature-Controlled Quartz Oscillators) | 1. Cesium or Rubidium Time Standards: NT$16,000 per unit 2. GPS Receivers: NT$16,000 per unit 3.Second-Level Items: NT$8,500 per unit 4.Third-Level Items: NT$4,500 per unit | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Frequency Measurement | 1. Second-Level Items (Temperature-Controlled Quartz Oscillators) 2. Third-Level Items (Below Temperature-Controlled Quartz Oscillators) 3. Microwave Frequency Signal Generators | 1. Second-Level Items: NT$8,500 per unit 2.Third-Level Items: NT$4,500 per unit 3.Microwave Frequency Signal Generators: NT$25,000 per unit (For calibration frequency points equal to or less than 5; for more than 5 points, an additional NT$5,000 per point) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Phase Comparison | 1. Cesium or Rubidium Frequency Standards 2. GPS Receivers | 1. Cesium or Rubidium Frequency Standards: NT$16,000 per unit 2. GPS Receivers: NT$16,000 per unit | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Frequency and Phase Measurement | Items for Calibration: Cesium Frequency Standards | Fee Standard: NT$16,000 per unit | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Remote Frequency Calibration | Items for Calibration: Various Atomic Clock Frequency Standards, Various Quartz Oscillators | Fee Standard: NT$20,000 per unit | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Portable Cesium Clock Time Measurement | 1.Cesium or Hydrogen Time Standards 2.Rubidium Time Standards or GPS Receivers 3.Second-Level Items (Temperature-Controlled Quartz Oscillators) | Fee Standard: NT$30,000 per unit | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||