Instrument Calibration
Yokogawa instrument calibration ensures quantifiable confidence in the measurement system and its results. Calibration guarantees that the instruments perform within their published specifications, which is critical for maintaining accurate and reliable measurements.
Key Reasons for Calibration
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Guaranteed Specifications: There is always a finite error between a measured value and the true value. Over time, this error can increase due to factors like drift, environmental changes, and wear. Regular calibration minimizes these errors and guarantees the instrument’s performance within the published specifications.
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Confidence Over Time: Instrument readings can drift over time. Calibration restores the instrument's precision by adjusting and validating to traceable standards, providing confidence and reliability in the measurement system over long-term use.
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Reduced Risk: In many industries, product performance and compliance must be guaranteed and traceable. Calibration provides traceablility to recognized measurement standards, reducing the risk of non-compliance, ensuring product safety and performance.
Products Supported
Yokogawa provides calibration services for all of our electrical and optical measurement instruments:
| Optical Instruments | Power Instruments | Waveform Measuring Instruments | General Purpose Instruments | Standards |
| Optical spectrum analyzers | Power analyzers | ScopeCorders | Function generators | AC calibrators |
| Optical power meters | Power meters | Data recorders | Source measure units | DC calibrators |
| Light sources | Current transformers | Data loggers | Insulation testers | DC voltage standards |
| Oscilloscopes | Digital multimeters | |||
| Waveform analyzers | Decade resistance boxes |
Accreditations
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NIST (US) / ANSI Z540: Calibration services traceable to the National Institute of Standards and Technology (NIST) and ANSI Z540 standards.
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ISO 17025: Yokogawa offers ISO 17025-accredited calibration services, which provide assurance of the technical competence of the laboratory. The scope of accreditation covers various types of measurement equipment and ensures that calibrated instruments meet stringent requirements. ISO 17025 requires external audits of the calibration process itself. Yokogawa's calibration laboratory is certified by A2LA (American Association for Laboratory Accreditation) and performs calibrations in accordance with ISO/IEC 17025:2017 and ANSI/NCSL Z540-1-1994 (A2LA Certificate Number 3474.01).
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ISO 9001: Yokogawa Corporation of America has adopted Quality Management principles based on the International Standard for Quality Management, ISO 9001, and has maintained ISO 9001 Certification since 1996. This provides quality assurance in all processes related to instrument calibration services.
Calibration Service Agreements
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One-Time Calibration: Customers can opt for one-time calibration services, whether for new instruments or for recalibration at the customer's desired calibration interval. Annual calibrations are a common approach for businesses seeking certification or validation of equipment.
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Multi-Year Agreements: YCA offers multi-year calibration service agreements for annual calibration that provide added value for long-term customers, including reduced rates for ongoing services, instrument cleaning and refurbishing.
Yokogawa Corporation of America operates a highly specialized, A2LA accredited calibration laboratory in Newnan, Georgia, USA. This ensures the lab adheres to strict quality management and technical competency requirements.
Comprehensive Instrument Testing
Compared to some third party calibration laboratories, Yokogawa's calibration lab performs more comprehensive tests across all ranges, test points, and channels as specified by Yokogawa's strict Quality Inspection Standards (QIS). This ensures that instruments are thoroughly tested for precision and accuracy across a full range of operational conditions.
Out-of-Tolerance Adjustments
Yokogawa doesn't only validate calibration accuracy, but also adjusts instruments using specialized Yokogawa procedures. These procedures are developed by Yokogawa engineers to enable measurement calibration and ensure they meet factory standards. When test data exceeds 70% of the specified band, adjustments are made to the instrument firmware or hardware to bring it back into compliance, extending the instrument's operational life.
Repair Services
Calibration failures can sometimes be indicative of deeper mechanical or electrical issues. In such cases, the lab provides repair services, leveraging Yokogawa’s extensive knowledge of its instruments. After repair, recalibration is conducted to confirm that the instrument is functioning properly, ensuring it is returned in optimal condition.
Turnaround Times and Care Advice
The typical turnaround time for calibration services at the Newnan lab is approximately 7-10 business days, though this may vary depending on the complexity of the instrument or repair needs. For critical applications, expedited services may be available upon request.
To protect instruments during transit, Yokogawa advises customers to:
- Use a hard case: Whenever possible, package your instruments in a sturdy hard case designed for sensitive electronic equipment.
- Use original packaging if possible or pack instruments securely using adequate padding materials.
- Ensure that the instruments are properly cushioned to prevent shock or damage.
- Label the package with “Fragile” or “Sensitive Electronics” to alert handlers to take extra care.
- Include detailed documentation of the instrument’s condition and calibration request to avoid delays.
How to Request Calibration
If you need an instrument to be calibrated, please contact your local representative for a quotation.
Please note that you will need to complete the Calibration Return Authorization Request form, with the instrument details, so that our local representative can provide you an appropriate quote.
NIST
- Example NIST AQ6370E calibration certificate
- Example NIST DL950 16 Bit Isolation Module calibration certificate
- Example NIST DL950 Temperature Voltage Module calibration certificate
- Example NIST WT5000 5A Module calibration certificate
- Example NIST WT5000 30A Module calibration certificate
- Example NIST WT5000 Current Sensor Module calibration certificate
ISO17025
- Example ISO17025 DL950 16 Bit Isolation Module calibration certificate
- Example ISO17025 DL950 Temperature Voltage Module calibration certificate
- Example ISO17025 WT5000 5A Module calibration certificate
- Example ISO17025 WT5000 30A Module calibration certificate
- Example ISO17025 WT5000 Current Sensor Module calibration certificate
Samples for other instruments can be provided upon request.
Laboratory Decision Rule for ISO17025 Accredited Calibrations
In ISO/IEC 17025:2017, the decision rule is a key concept that defines how measurement uncertainty is considered when stating conformity with a specified requirement. The decision rule clarifies how a laboratory interprets test or calibration results relative to specified limits (e.g., tolerance, specifications) while taking uncertainty into account.
This statement provides advance notice of the decision rule used by Yokogawa’s calibration laboratory when providing calibration certificates. The laboratory uses a guard-band method which is described as follows:
- ILAC-G8:03/2009 The guard-band (G) is the specification (S) minus the expanded uncertainty (U) at a 95% confidence interval:
G = S - U95%
Measurement results are reported as follows:
- Passed (Pass) The measured values of the equipment were observed in specification at the points tested. Additionally, the expanded measurement uncertainty intervals about the measured values were in specification.
- Passed Indeterminant (Pass?) The measured values of the equipment were observed in specification at the points tested. However, a portion of the expanded measurement uncertainty intervals about one or more measured values exceeded specification. Consequently, compliance with specification cannot be declared based on the stated coverage probability.
- Failed Indeterminant (Fail?) One or more measured values of the equipment were observed out of specification at the points tested. However, a portion of the expanded measurement uncertainty intervals about one or more measured values were in specification. Consequently, non-compliance with specification cannot be declared based on the stated coverage probability.
- Failed (Fail) One or more measured values of the equipment were observed out of specification at the points tested. Additionally, the expanded measurement uncertainty intervals about one or more measured values were entirely outside the specification.
In the circumstance that the methodology described above is not acceptable, it must be communicated at the time of request to Yokogawa. Yokogawa’s calibration laboratory will strive to comply with reasonable decision rule requests, though it is possible that complexity or laboratory constraints will interfere with certain requests.
Q: What is the difference between calibration and adjustment?
Calibration compares a measuring instrument's performance against a national standard of known accuracy to gain quantifiable confidence in its measurement system. This determines if there is a need to then adjust the instrument and to what extent. Instruments are initially adjusted at the factory to indicate a value that is as close as possible to the currently-accepted known standard of accuracy. Measurement uncertainties of the known standard dictate the confidence that the value from the intial adjustment is "correct." Over time, this initial value may drift due to environmental factors (temperature, humidity, oxidation, loading, etc.), which are also dependent on the quality of its design and manufacture. Regular comparison of an instrument's performance to known standards ensures it continues to operate within the manufacturer's tolerances as the instrument can once again be adjusted to meet the standards.
Q: How often should Yokogawa instruments be calibrated?
A: Yokogawa recommends annual calibration for their test and measurement instruments to ensure accuracy and reliability. However, the calibration interval ultimately depends on the customer's decision and key factors surrounding their application:
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Environmental Considerations: External conditions like temperature, humidity, or physical shocks can cause or accelerate drift. Instruments that experience harsh operating conditions might require recalibration sooner than those in stable environments.
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Application-Specific Requirements: Instruments used in high-precision applications or those subjected to varying conditions may need calibration more often than those used in stable environments. Calibration before and/or after major critical testing projects also ensures the least measurement uncertainty to support decision making.
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Industry Standards: Different industries may have specific requirements for calibration frequency, which could necessitate more frequent checks based on compliance needs.
Q: What is ISO/IEC 17025:2017?
The International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) first issued the standard in 1999. Recognized globally, it is the single most important standard for calibration laboratories. Labs accredited to this international standard demonstrate technical competence and produce test and calibration data that is precise and accurate.