Calibration Guide. Reliability through traceability

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1 The Golden Ratio. Ever since the ancient times mathematicians, architects, artists, and composers studied this phenomenon. Even in nature, we find the Golden Ratio. A special measure with special applications. VSL, The Art of Measurement Calibration Guide Reliability through traceability VSL Thijsseweg JA Delft P.O. Box AR Delft The Netherlands T +31 (0) F +31 (0) E info@vsl.nl I

2 Beyond all doubt Reliability through traceability This guide gives an overview of calibrations that VSL can perform for you. Your choice for VSL is a choice for high level calibrations with the highest reliability. VSL makes measurement results of companies, laboratories and organisations directly traceable to international standards. The Dutch government has appointed VSL to maintain and develop the national measurement standards. VSL makes an important contribution towards the reliability, quality and innovation of products and processes, both within businesses and in society at large. It is important that you can have confidence in the results of your measurements. After all, the quality of your measurement is closely linked to the quality of the product or service you provide. It is important that your measurement value is comparable with that found by others but also that your current measurement value can be compared with that of last year. A timely and correct calibration of your measuring equipment is essential for this purpose. Apart from calibrations, VSL offers reference materials for gas analysis, viscosity and mineral oil. International traceability A calibration by VSL implies a direct comparison to a primary measurement standard. VSL is the National Metrology Institute of the Netherlands and maintains and develops the national measurement standards. The chain between the primary standard and your equipment is as direct as possible when having your equipment calibrated at VSL. This ensures the lowest possible measurement uncertainty. VSL operates in the centre of the international metrological infrastructure. Our certificates are widely recognised via the CIPM Mutual Recognition Agreement (MRA). and planning At a certain moment, recalibration of your equipment will be required. We can guide your organisation in determining the relevant recalibration period and initiate timely recalibration. Careful planning can prevent the loss of valuable time. You can read more about our ISO accreditation scope on and you can find everything about our calibration & measurement capabilities (CMC) on 3 Calibration Guide Reliability through traceability

3 1 Chemistry Our customers wish to underpin their quality system. Our Primary Reference Gas Mixtures facilitate this. VSL provides Primary Reference Gas Mixtures that are used worldwide to make gas composition measurements traceable and comparable. These internationally accepted mixtures are used in both industrial and environmental analyses in a wide field of applications. Typical applications vary from volatile organic compounds to natural gas. VSL is strong in the calibration of gas monitors and the analysis of gas mixtures of third parties in addition to the supply of gas mixtures. The gas mixtures are prepared via gravimetric methods (ISO 6142) and validated by comparison with standard gas mixtures. Gas mixtures of third parties are analysed and are also compared with these standard gas mixtures. The method described in ISO 6143 is used for the comparison. VSL reports the linearity over the desired measurement range for gas monitors. Applications and clients Most suppliers of specialty gases use the Primary Reference Gas Mixtures from VSL to underpin their quality system and to provide their clients with international traceability. For example: the calorific value, which relates directly to the price of natural gas, is determined by both buyer and seller with a gas chromatograph traceably calibrated to VSL. 4 Calibration Guide Reliability through traceability 5

4 2 Light We provide an extensive range of services aimed at LED-based products as well as conventional calibrations of light sources, light measurement systems and optical materials. VSL provides traceability via calibration and reference standards in the field of light measurements. We have an extensive range of services aimed at the characterization of LED-based products, as well as conventional calibrations of light sources, light measurement systems and optical materials. Our services provide certainty to clients so that they can guarantee the quality of their products or services. The metrological basis for all light measurements originates from a cryogenic radiometer, with which detectors are calibrated in terms of spectral responsivity. These detectors are utilized to achieve the internationally recognized national standards realized at VSL. Consequently these detectors are used as transfer standards to calibrate a huge variety of light sources, light measurement systems or optical materials. Applications and clients The services provided by VSL are important for a wide scale of applications. Specific application areas are for example public lighting, interior lighting, maritime and obstruction lighting, operating theatre lighting, and bio- and pharmaceutical research. We provide our services to manufacturers of light sources and measurement systems, authorities, hospitals and research institutions. 6 Calibration Guide Reliability through traceability 7 Calibration Guide Reliability through traceability

5 3 Electricity VSL enables its clients to demonstrate the quality and reliability of their products and services by the calibration of their measuring equipment. Electricity is often used as the medium to transport information or energy from one place to another. Accurate electrical measurements are essential in this. VSL provides the basis of all these measurements with measurement facilities for a large number of quantities (voltage, resistance, current, power) over wide frequency and measurement ranges. VSL enables its clients to demonstrate the quality and reliability of their products and services by the calibration of their measuring equipment. The metrological starting point of all electrical measurements are the primary standards for voltage and resistance, which are based on intrinsically stable and accurate quantum effects. All other electrical quantities are derived of these quantum standards using special scaling and conversion equipment. This ultimately produces a measurement range of the VSL facilities varying from nanovolts to kilovolts and a frequency range from DC to 50 GHz. Applications and clients The service provided by VSL means that the quality of the measurement values is guaranteed whether it concerns billing of electrical energy between client and supplier or proof of specifications of newly developed measuring equipment. VSL provides services to a wide range of companies and institutes, e.g. accredited measurement and testing laboratories, manufacturers of measuring equipment, energy companies, universities and defence laboratories. 8 Calibration Guide Reliability through traceability 9 Calibration Guide Reliability through traceability

6 4 Length and geometry VSL has a complete range of facilities in dimensional measurement techniques: length, diameter, shape or angle, from more than a metre to nanometre level, in 1D, 2D or 3D. VSL has a complete range of facilities in dimensional measurement techniques: length, diameter, form or angle, from more than a metre to nanometre level, in 1D, 2D or 3D. This enables VSL to measure your product or prototype with a high degree of accuracy, and also to calibrate your measurement instruments or standards. Either in our high quality measurement laboratories or at your premises. All our measurements are traceable back to the metre, the 1/ th part of the distance light travels in a second in vacuum. The Dutch metre is a special iodine stabilised He-Ne laser. In practice, a measured distance is compared directly or indirectly to the wavelength of a laser interferometer whose frequency is compared to that of the standard laser. Application and clients Measurements must be efficient and reliable wherever the dimensions of a product are important. Measurement departments in manufacturing companies use VSL to calibrate their measurement standards and instruments. Reliable measurements form an important part of the incoming and outgoing quality control. Producers of length measuring equipment ask VSL to provide their products with an internationally recognised certificate. VSL can make product measurements for companies in the high-precision industry with the highest attainable accuracy. 10 Calibration Guide Reliability through traceability 11 Calibration Guide Reliability through traceability

7 5 Ionising radiation and radioactivity VSL offers a wide range of services in the field of ionising radiation and radioactivity, for example calibration of dosimetry equipment, radiation level and contamination monitors and well-type ionisation chambers. VSL offers a wide range of services in the field of ionising radiation and radioactivity, for example calibration of dosimetry equipment, radiation level and contamination monitors and well-type ionisation chambers. VSL also provides calibration and dosimetry audits of radiation beams on location. VSL continually keeps abreast of the developments in health care and industry. In this way VSL helps its clients to guarantee the quality of their services. VSL has a large number of national and derived standards to provide traceability. With regard to dosimetry, these are standards for absorbed dose to water and kerma in air in high and medium energetic photon beams. Calibrations are made in gamma radiation beams of cobalt-60 and cesium-137 and in X-ray beams with a tube voltage between 10 kv and 320 kv. VSL also has various standards for activity measurements, which are used for calibrations using radioactive sources. Application and clients VSL provides traceability for radiotherapy (teletherapy and brachytherapy), radiobiology, nuclear medicine, medical diagnostics, mammography and radiation protection purposes. Clients include hospitals, radiotherapy institutes, international authorities, recognised dosimetry services, nuclear power stations and manufacturers of radiation and diagnostic equipment. 12 Calibration Guide Reliability through traceability 13 Calibration Guide Reliability through traceability

8 6 Time and frequency VSL provides the most accurate calibrations in the field of time and frequency in The Netherlands. VSL provides the most accurate calibrations in the field of time and frequency in The Netherlands. This is possible because VSL is responsible for maintaining the national time and frequency standard. VSL also provides synchronisation services in the form of a Time Bulletin and for computers via the Internet and a telephone service ( )*. These services ensure reliability and quality assurance within a wide range of applications. The national time and frequency standard maintained at VSL is based on four atomic clocks. These clocks are included in a worldwide network, which jointly determines the international time scale (UTC) and the duration of the second. VSL uses frequency dividers and multipliers to achieve an extensive frequency range. Application and clients Time and frequency are widely used quantities in daily life. They are used in various industrial processes, electronic data integrity systems, telecommunication, astronomy, geodesy, navigation, medical research, and for leisure time activities, e.g. sporting events. Clients are therefore found in a wide application field, such as manufacturers and suppliers of frequency and time measuring instruments, research institutes, defence, telecom and Internet providers and banks. * only available in the Netherlands 14 Calibration Guide Reliability through traceability 15 Calibration Guide Reliability through traceability

9 7 Flow VSL has facilities to perform calibrations over a wide flow range and can calibrate virtually all types of industrial flow meters. VSL calibrates flow meters for both gases and liquids. VSL has facilities to perform calibrations over a wide flow range. With these facilities almost all types of industrial flow meters can be calibrated. The performance characteristics of new flow meters can be tested against their specifications. We offer the lowest possible uncertainty in volume and flow rate, which allows accurate billing of the supplied amount of oil and gas. The primary standard for flow (cubic metres per second) is based on standards for mass and time. Our standards are regularly compared with those of other National Metrology Institutes, so that international comparability is guaranteed. During calibration in the laboratory, the meter under test is positioned inline with a reference meter. This enables us to determine the measurement error and uncertainty. Applications and clients Most of the flow meters we calibrate are from customers in the oil and gas industry. These gas and liquid flow meters are often for billing purposes. In process and chemical industry, flow meters are used to determine volumes of various component streams. Furthermore, VSL calibrates many flow meters for equipment suppliers, utility companies and gas transport and distribution companies. 16 Calibration Guide Reliability through traceability 17 Calibration Guide Reliability through traceability

10 8 Temperature and humidity An accurate knowledge of temperature and humidity is important in countless processes in industry and science. VSL provides clients with accurate temperature and humidity calibrations for a wide variety of instruments. An accurate knowledge of temperature and humidity is important in countless processes in industry and science. VSL provides clients with accurate temperature and humidity calibrations for a wide variety of instruments. VSL also carries out special measurement projects such as the characterization of advanced measurement systems. VSL realizes and maintains the full range of the current International Temperature Scale (ITS-90) from -273 C to C, through primary standards based on highly-reproducible phase transitions of ultra-high purity materials (temperature fixed-points). At VSL the clients thermometers are calibrated by direct comparison with the primary standards or by comparison with thermometers directly traceable to the primary standards. Likewise dew-point hygrometers (e.g. chilled mirror hygrometers) are calibrated at VSL by direct comparison with a primary humidity standard that is based on the principle of complete saturation of a carrier gas at known temperature and pressure (dew-point generator). Other humidity sensors are calibrated in a climatic chamber by comparison with chilled mirror hygrometers directly traceable to the primary standard. Application and clients Clients of VSL often have a direct or indirect interest in process applications in which temperature and humidity play an important role. Examples of this can be found in the petrochemical industry, energy production, health care and environment. VSL also provides its services to manufacturers of sensors and to calibration laboratories. 18 Calibration Guide Reliability through traceability 19 Calibration Guide Reliability through traceability

11 9 Mass Mass is very important in many industries because incorrect mass measurements can lead to serious errors. VSL provides traceability and accurate mass calibrations to help clients to avoid these problems. VSL provides traceability in the field of mass measurements and achieves the highest accuracy in the Netherlands. Accurate weighing is in many cases essential when it concerns safety, health or costs. VSL calibrates and adjusts weights of class M1 to class E1 for which the conventional mass, the true mass and the Newtonian mass can be determined. For the calibration of weights for clients, VSL uses high-class mass standards that are directly derived from the Dutch kilogram, which in turn is traceable back to the international kilogram in Paris. This short traceability chain and the use of weighing robots guarantee a very low measurement uncertainty. Application and clients Mass measurements play an important role in trade, industry, analytical laboratories and process control. For example, mass standards are used to calibrate weighing instruments and to adjust them if necessary or they are used in accredited organisations to determine the mass of other weights. 20 Calibration Guide Reliability through traceability 21 Calibration Guide Reliability through traceability

12 10 Viscosity Viscosity plays an important role in many industries. With certified reference materials supplied by VSL, the viscosity of products is traceable and can be determined accurately. VSL provides certified reference materials with a fixed kinematic or dynamic viscosity for various temperatures. It is also possible to calibrate the viscosity and density of liquid samples or to determine viscosimeters. VSL is the only organisation with an ISO accreditation for viscosity in The Netherlands. The basis for all viscosity measurements is the internationally determined viscosity of double-distilled water. VSL calibrates its primary Ostwald viscosimeters with this water and uses liquids with increasing viscosity to calibrate the other viscosimeters, which in turn are used to determine the viscosity of unknown liquids and reference materials. All these measurements are performed in a temperature controlled bath, which can be set at various temperatures. Application and clients Viscosity is important in the food, paint, automobile, pharmaceutical, cosmetic and chemical industries, where it is widely used for quality and process control. Reference materials are used to calibrate viscosimeters, which can be used to investigate samples or to perform trend analyses. 22 Calibration Guide Reliability through traceability 23 Calibration Guide Reliability through traceability

13 11 Pressure In many industries pressure measurements are very important. With pressure gauges and deadweight testers calibrated by VSL, those pressure measurements are traceable, accurate and reliable. VSL calibrates and adjusts pressure gauges and deadweight testers with a low measurement uncertainty. Both absolute and relative pressure measurements are possible. Pressure plays an important role in many processes in connection with quality or safety. Certainly now that more processes are automated, it is of great importance for the pressure measurements to be accurate and reliable. Pressure measurements are made by means of a cross float with deadweight testers. These are traceable to the Dutch standards for mass, length and time. During the calibration, corrections are made for various effects that can influence the measurement, such as temperature and gravitation. Application and clients Traceable pressure measurements are widely used in the process industry, health care, the oil and gas industries, and in analytical and chemical laboratories. VSL provides its services to parties that are active within these fields. VSL also provides its services to accredited organisations that use deadweight testers for the calibration of pressure gauges. 24 Calibration Guide Reliability through traceability 25 Calibration Guide Reliability through traceability

14 Index 1 Chemistry 4 2 Light 6 3 Electricity 8 4 Length and geometry 10 5 Ionising radiation and radioactivity 12 6 Time and frequency 14 7 Flow 16 8 Temperature and humidity 18 9 Mass Viscosity Pressure 24 Colophon Publication: VSL, Delft Concept, design and text: Smidswater, Den Haag Photography: Aksento, Breda Print: Lecturis, Eindhoven