Accredited Calibration Services and TS EN ISO/IEC 17025 Measurement Solutions

The accuracy of decisions made in industrial production processes, laboratory analyses, medical applications, and occupational safety inspections depends on the reliability of the measurement instruments used. A temperature sensor providing incorrect readings, a scale yielding erroneous weight measurements, or a manometer showing deviations can lead to faulty production, product recalls, costly waste, and—most importantly—risks to human safety. Calibration Services—which verify and document the accuracy of your measurement equipment by comparing it against international reference standards—constitute the fundamental building block of quality management systems.

Our engineering and calibration organization provides accredited calibration, traceability analysis, and measurement uncertainty calculation services to all sectors of the industry, in compliance with the rigorous technical requirements of the TS EN ISO/IEC 17025 standard, leveraging advanced laboratory infrastructure, controlled environmental conditions, and expert calibration engineers.

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1. What Is Calibration? Conceptual Truths and Misconceptions

One of the most common mistakes in the industry is viewing calibration as a "repair" or "device adjustment" process. According to the definitions of the International Committee for Weights and Measures (CIPM), calibration is the process of establishing a relationship—under specified conditions—between the values ​​indicated by a measuring instrument or system and the values ​​of a known reference standard (etalon).

In short, calibration is the process of determining and documenting not **how accurately** a device measures, but rather the **degree of deviation** with which it measures. No mechanical intervention is performed on the device as a result of calibration; instead, the device's current state is reported—along with its measurement uncertainty values—in a **Calibration Certificate**. If the device falls outside legal tolerance limits, it is directed for "Adjustment" or "Repair" following the calibration, and the calibration process is subsequently repeated.

Differences Between Calibration, Verification, and Adjustment:

• Calibration: The process of recording the amount of deviation and measurement uncertainty of a device relative to a reference standard (determining the current status).
• Verification: The process of checking whether the device's measurement deviation falls within predetermined legal or technical tolerance limits (e.g., ISO 9001 or pharmaceutical industry limits) and making a "Compliant/Non-compliant" determination.
• Adjustment: The process of physically, electronically, or mechanically optimizing a measuring device to ensure it displays accurate values.

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2. Why Is Calibration Necessary? Legal and Quality Requirements

In the industrial world, calibration is not a luxury or an optional practice; it is a legal and operational necessity for maintaining a presence in the global market. The key benefits of regular calibration for your business include:

2.1. Compliance with Quality Management Systems (ISO 9001, IATF 16949, ISO 22000)

Standards such as ISO 9001 (Quality Management System), IATF 16949 (automotive sector), ISO 22000 (food sector), and ISO 13485 (medical devices) mandate the traceable calibration of measuring instruments. During audits, even a single instrument lacking a calibration certificate or having an expired calibration interval constitutes grounds for a major non-conformity.

2.2. Cost Optimization and Reduction of Scrap Rates

On precision production lines (e.g., defense industry, aerospace, or plastic injection molding), a caliper or micrometer operating outside tolerance limits can result in an entire production batch having incorrect dimensions. Deviations that go undetected early on lead to wasted raw materials, lost labor, and customer complaints. Calibration eliminates these hidden costs.

2.3. Energy Efficiency and Process Safety

In industrial furnaces, boilers, and reactors, a deviation of 1°C or 0.5 bar in temperature or pressure compromises product quality and leads to massive energy losses. More importantly, faulty pressure gauges on high-pressure lines create a risk of explosion. Calibration is the safeguard of process safety.

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3. Calibration Sub-disciplines Based on Our Areas of Expertise

Our laboratory holds an extensive accreditation scope covering all physical, mechanical, and electrical quantities required by the industry. The sector-specific calibration solutions we offer are as follows:

3.1. Temperature and Humidity Calibration

Stability in temperature and relative humidity values ​​is vital for food storage areas, cold chain logistics, pharmaceutical warehouses, heat treatment furnaces, and incubators. Our temperature calibrations are performed using dry-block calibrators, liquid baths, and high-precision standard platinum resistance thermometers (SPRTs).

• Calibration of Drying Ovens, Incubators, Climate Chambers, and Cold Rooms (Temperature Distribution Analysis)
• Digital and Analog Thermometers, Thermocouples (Types R, S, K, J), and Pt100 Sensors
• Infrared Pyrometers and Thermal Cameras
• Digital and Mechanical Hygrometers (Humidity Meters)

3.2. Pressure Calibration

Pressure values ​​for all equipment covered by the Pressure Equipment Directive (PED), as well as hydraulic/pneumatic systems and in-line instruments, are tested using high-precision dead-weight testers and digital reference manometers. Calibrations are reliably performed across a range extending from vacuum levels up to high-pressure (bar) levels.

• Analog and Digital Manometers and Vacuum Gauges
• Pressure Transmitters and Differential Pressure Sensors
• Safety Valve Opening/Closing Pressure Tests
• Pressure Switches (Pressostats)

3.3. Dimensional Calibration

To maintain micron-level precision in sectors such as machining, machinery manufacturing, automotive, and mold making, dimensional measuring instruments are calibrated in our specialized laboratory—maintained at a constant temperature of 20°C ±1°C—using master gauge blocks and laser interferometer systems.

• Digital, Analog, and Dial Calipers; Micrometers
• Run-out Gauges and Dial Indicators; Height Gauges
• Ring and Plug Gauges; Thread Gauges
• Optical Verification of Profile Projectors and Coordinate Measuring Machines (CMM)

3.4. Electrical and Electronic Calibration

Parameters such as current, voltage, resistance, frequency, and capacitance for instruments used in electrical panel testing, electronic circuit board manufacturing, R&D laboratories, and periodic electrical inspections are calibrated using multi-function calibrators (Multi-product Calibrators).

• Digital and Analog Multimeters; Clamp Meters
• Oscilloscopes, Signal Generators, and Frequency Counters
• Insulation Testers (Megger); Earth Ground Testers and Loop Impedance Meters
• Welding Machine Current/Voltage Displays

3.5. Mass and Balance Calibration

In the chemical, pharmaceutical, jewelry, and logistics sectors, weighing accuracy is directly linked to revenue and the precision of formulations.

Balance calibration is performed on-site using certified reference weight sets that comply with OIML (International Organization of Legal Metrology) classes (E2, F1, and M1).

• Analytical and Micro-Laboratory Balances
• Industrial Scales, Weighbridges, and Density Determination Kits
• Automatic Weighing Instruments and In-Line Checkweigher Systems

3.6. Volume and Liquid Flow Calibration

All volumetric equipment—ranging from liquid-transfer pipettes used in laboratories to flow meters on industrial lines—is calibrated using gravimetric (weighing) or volumetric methods.

• Automatic Pipettes, Micropipettes, and Burettes
• Glass Laboratory Ware (Volumetric Flasks, Graduated Cylinders, Erlenmeyer Flasks)
• Liquid Flow Meters and Flowmeters

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4. Comparative Calibration and Metrology Parameters Table

The table below summarizes the reference standards, acceptable standard environmental conditions, and typical calibration intervals for the calibration disciplines most frequently used in industry:

Calibration Discipline	Reference Standard Used	Ideal Laboratory Environmental Conditions	Recommended Interval
Dimensional	Class K Gauge Blocks, Optical Flats	20°C ± 1°C / 45% ± 10% RH	12 Months
Temperature	SPRT Resistance Thermometers, Fixed-Point Cells	23°C ± 3°C / 50% ± 15% RH	12 Months
Pressure	Dead Weight Tester	22°C ± 2°C / 45% ± 10% RH	12 Months
Electrical	8.5-Digit Reference Multimeter, Calibrator	23°C ± 1°C / 40% ± 10% RH	12 Months
Mass / Balance	Class E2 and F1 Stainless Steel Weights	Environmental conditions where the device is located	6 to 12 Months
Volumetric	High-Precision Balances, Pure Water	20°C ±

2°C / 50% ± 5%RH 12 Months

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5. What are TS EN ISO/IEC 17025 Accreditation and Traceability?

For a calibration certificate to be valid in the international arena, at customs checkpoints, in courts of law, or during international audits, it must meet two fundamental requirements: **Accreditation** and **Metrological Traceability**.

The Importance of the TS EN ISO/IEC 17025 Standard

This standard is a global quality benchmark certifying that a calibration laboratory is technically competent and that its test and measurement results are produced with complete accuracy. In Türkiye, this accreditation is granted by **TÜRKAK (Turkish Accreditation Agency)**. When you receive services from an accredited laboratory, your measurement results are recognized worldwide thanks to the ILAC (International Laboratory Accreditation Cooperation) mutual recognition agreement.

The Metrological Traceability Chain

Traceability is the property of a measurement result whereby it can be linked to a reference—usually international standards (the SI unit system)—through an unbroken chain of comparisons, each contributing to the measurement uncertainty.

For example, a caliper from your factory is calibrated against a master gauge in our laboratory. Our master gauge has been calibrated by the national metrology institute (TÜBİTAK UME). The standard at UME, in turn, is traceable to the primary standards held at the International Bureau of Weights and Measures (BIPM) in Paris. The moment this chain is broken, the calibration performed becomes nothing more than an invalid piece of paper.

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6. How Does the Step-by-Step Calibration Process Work?

To ensure full process traceability and a zero-error policy within our laboratory, calibration operations are carried out according to the following steps:

Step 1: Device Acceptance and Preliminary Inspection

Physical checks are performed on devices arriving at our laboratory or collected in the field. Battery status, display readability, and mechanical wear are inspected. Devices requiring cleaning are cleaned using ultrasonic baths or special solutions.

Step 2: Thermal Conditioning (Stabilization)

Dimensional and electrical devices, in particular, may expand or experience changes in resistance due to ambient temperature. Therefore, before calibration, devices are kept under our laboratory's reference environmental conditions (20°C ±1°C) for at least 24 hours to reach thermal equilibrium.

Step 3: Performing Measurements

Repeated measurements are taken at designated points in accordance with relevant national/international guidance documents (e.g., EURAMET guidelines) and in-house technical instructions. The data obtained is transferred to our digital automation system.

Step 4: Measurement Uncertainty and Deviation Calculations

Simply recording the measurement result is not sufficient. By accounting for all variables—such as reading errors by the engineer performing the measurement, the uncertainty of the reference standard, and fluctuations in ambient temperature—the **Expanded Measurement Uncertainty (U)** is calculated using a coverage factor of $k=2$ (at a 95% confidence level).

Step 5: Certification and Labeling

Once the calculations are complete, a calibration certificate compliant with the TS EN ISO/IEC 17025 standard is issued; this certificate includes the laboratory accreditation number and a statement of traceability. Additionally, a special, tear-resistant **Calibration Label**—displaying the calibration date, certificate number, and the next calibration due date—is affixed to the device.

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7. Frequently Asked Questions (FAQ) About Calibration Services

How should the calibration period (frequency) be determined?

International standards do not specify a fixed calibration period; the responsibility for determining this interval lies entirely with the user (the organization). When determining the period, factors such as the device's usage frequency, environmental conditions (dust, humidity, vibration), permissible process tolerances, and historical drift trends must be considered. While the general industry practice is a 12-month (1-year) interval, this period may be reduced to 3 or 6 months for critical devices.

What is the difference between accredited and non-accredited calibration?

Accredited calibration is a service provided by a laboratory whose measurement capabilities have been verified by a national accreditation body (such as TÜRKAK) and whose certificates hold international validity. In non-accredited calibration, the laboratory's traceability and measurement accuracy are not guaranteed by an official authority; such certificates are typically used for internal checks (outside of ISO 9001 requirements) or in rough processes, and they may not be accepted during official audits.

Do newly purchased, brand-new devices require calibration?

Yes, absolutely. The "Test Report" or "Certificate of Conformity" documents included by manufacturers in the device packaging are generally not calibration certificates. The logistics processes the device undergoes—as well as the vibrations and temperature fluctuations it is exposed to—between leaving the factory and reaching you may have compromised its geometry or electronics. Performing a "Day Zero Calibration" before introducing the device to the production line is the safest approach.

What does the "Uncertainty" value on a calibration certificate indicate?

No measurement in the world is 100% precise; every measurement carries a margin of doubt. The measurement uncertainty stated on the certificate is a statistical parameter indicating the range within which the true value of the measurement lies. For example, if your temperature measurement is 100°C with an uncertainty of ±0.2°C, it is established with 95% confidence that the actual temperature falls between 99.8°C and 100.2°C. The lower the uncertainty value, the more precise the calibration.

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Ensure Measurement Precision and Quality

Calibration certificates that fail to meet regulatory standards, lack verifiable metrological traceability, or contain erroneous uncertainty calculations put your business at risk during audits and damage your reputation with customers. Entrust your calibration processes to professionals to elevate your production quality, pass legal audits with zero non-conformities, and build trust in the global market. **Contact our expert engineering team today** for customized price quotes tailored to your project and equipment inventory, as well as on-site calibration services.