Calibration FAQs
What is calibration?The accuracy of the electronic components used in all instruments naturally drifts over time. Time in service as well as environmental conditions also add to this drift. As time progresses, changes in component properties will cause greater uncertainty in your measurements. Eventually, the drift causes the instrument’s uncertainty to become undefined, meaning the manufacturer can no longer predict the uncertainty and guarantee measurement results. To resolve this issue, instruments must be calibrated at regular intervals as defined by the manufacturer. Calibration involves comparing an instrument’s performance to a standard of known accuracy. The result of a calibration may be documentation showing the deviation of a measurement from the known standard or it may also include adjusting the instrument’s measurement capability to improve measurement accuracy. Calibration is intended to quantify and improve the measurement accuracy of your instrument. The benefits of maintaining properly calibrated equipment include:
For most measurement devices, NI supplies graduated accuracy tables, providing you with a better uncertainty profile for the life of your measurement device. NI recommends that you periodically calibrate your hardware to ensure measurement accuracy and to keep your devices operating in peak precision. Why is calibration important?Electronics components’ physical properties naturally drift because of the effects of time, stress, and environment. Without periodic calibration, the measurements made by circuits composed of these components become uncertain. Periodic calibration minimizes the uncertainty of these components based on a standard of known accuracy, resulting in an instrument that is capable of making accurate, repeatable measurements. An investment in routine calibration ensures quality and customer satisfaction. Improperly maintained test equipment can cost you money by impacting your customer’s success and results in unscheduled downtime, costly quality problems, and product recalls. TraceabilityTraceability is the unbroken chain of comparisons between your measurement device and national or international standards. At the top of the traceability chain, the Bureau International des Poids et Mesures (BIPM) ensures worldwide uniformity of measurements and their traceability to the International System of Units (SI). It does this with the authority of the Convention of the Metre, a diplomatic treaty between 51 nations. The BIPM also organizes international comparisons of national measurement standards, and carries out calibrations for member states. At the national level, different legal metrology authorities exist for each country. They follow guidelines from BIPM and its associated committees to provide quality measurements standards for their associated country. The National Metrology Institutes (NMI) of each member state of the Convention of the Metre also participates in the mutual recognition agreement (MRA), which provides a mutual recognition of calibration and measurement certificates issued by NMIs. Finally, each country maintains accreditation institutes that audit and accredit local metrology. In Europe, many of these accreditation institutes participate in the EA multilateral agreement (MLA) to ensure that accreditations in one country are acceptable in another. Find detailed information at www.bipm.org/en/home NI products are calibrated at manufacturing and are traceable to national and international standards. Products returned to NI by customers in the Americas and Asia for basic calibration service also receive NIST traceable calibration. In Europe, basic calibration service is traceable to EUROMET approved standards such as PTB in Germany or NMI in the Netherlands. UncertaintyThe result of any measurement is only an approximate estimate of the “real” value being measured. The real value can never be perfectly measured, because there is always some physical limit to how well we can measure a number. For example, the specifications of the PCI-6070 state that if configured in the +/-10 V range and measuring a signal of 9.5 V the error from the nominal reading can vary by as much as ±14 mV. Therefore, one part of the uncertainty of any measurement taken in the +/-10 V DC range is ±14 mV. We say “one part” because other factors contribute to the total uncertainty of the measurements, including the uncertainties associated with all of the devices used to calibrate the board as well as the statistical error associated with the measurement. If you were to use the DAQ board to measure the same value – say 9.5 V – one hundred times, then you would expect to get 100 different answers. Yes, the answers would be very close (most likely within ±14 mV of each other), but they would not be the same. Many systems average the returned data and report the average as the measurement. To determine the statistical uncertainty, take the standard deviation of all of the measurements and include this value as part of the overall uncertainty of the measurement. In metrology these uncertainties are referred to as Type A and Type B uncertainties. Type A uncertainties are those due to statistical methods. Type B uncertainties are systematic (gain, offset, and so on). How often does my device need to be calibrated?After a period of time, a manufacturer can no longer predict the uncertainty and guarantee measurement results. To resolve this issue, instruments must be calibrated at regular intervals as defined by the manufacturer. This calibration interval is provided in the product manual. However, this interval is only a recommendation. An instrument must be calibrated as often as needed to provide the level of accuracy for the needs of the application. As drift tends to worsen over time, an application that requires a high level of accuracy may require that the device be calibrated at more frequent intervals than recommended by the manufacturer. Are all NI products calibrated?National Instruments manufactures many types of products. While some do not require calibration, the majority of test and measurement products that NI manufactures do require calibration to maintain measurement accuracy. To determine if your device requires periodic recalibration, consult the product manual for the specified calibration interval or refer to the calibration product and price list for a complete list of calibrated products and available services.  Supported Products, Prices, and Part Numbers (147 KB PDF)
What is the difference between basic and detailed calibration?
Does NI provide express or on-site calibration services?Through independent calibration services partners, NI can provide additional calibration services for NI products such as express calibration services, on-site calibration services, and calibration services for instrumentation products that are not from NI. List of Calibration Services PartnersThrough independent calibration services partners, NI can provide additional calibration services for NI products such as express calibration services, on-site calibration services, and calibration services for instrumentation products that are not from NI. AmericasDavis Calibration 2324 Ridgepoint Dr. #D Austin, TX 78754 USA Phone: (512) 926-7625, 800-365-0147 Fax: (512) 926-8450 Web: www.daviscalibrationlab.com Europe esz Elektronik-Service GmbH Max-Planck-Str. 16 D-82223 Eichenau Germany Tel: +49-8141-88887-0 Fax: +49-8141-88887-77 E-mail: info@esz-GmbH.de Web: www.esz-gmbh.de] Asia/Pacific Singapore Technologies Electronics Ltd. 24 Ang Mo Kio Street 65 Singapore 569061 Phone: (65)6413 1907 Fax: (65)6484 5357 E-mail: cal@juzclickcal.com Web: www.juzclickcal.com Japan Tsuryo Technica K.K. 661-0001 Hyogo-ken Amagasaki-shi Tsukaguchi Honmachi 8-1-1 Tel: 06-6495-5548 (Japanese only) Fax:06-6495-6946 (Japanese only) Web: www.tsuryo.co.jp (Japanese only) For English, contact Nihon National Instruments Tel: 03-5472-2970 E-mail: salesjapan@ni.com Independent Calibration ProvidersThe following independent laboratories provide local calibration services for NI products. These labs are not directly affiliated with National Instruments. NI recommends that you research their capabilities before using their services. AmericasPrecision Metrology Contact: Carol Shipley 7350 N. Teutonia Ave. Milwaukee, WI 53209 Tel: (414) 351-7420 Fax: (414) 351-7429 E-mail: carol@precisionmetrology.com Web: www.precisionmetrology.com Dynamic Technology Contact: Lonnie Spires 1200 N. Old U.S. 23 Hartland, MI 48353 Tel: (810) 225-4601 Fax: (810) 225-4602 E-mail: lspires@dynamictechnology.com Web: www.dynamictechnology.com SE Laboratories Contact: Dan Turgeon 1065 Comstock Street Santa Clara, CA 95054 Tel: (408) 844-7215 (Direct) Tel: (408) 727-3286 (Main) Fax: (408) 988-6186 E-mail: dturgeon@selabs.com Web: www.selabs.com Anmar Metrology, Inc. Contact: Larry Newman 7726 Arjons Drive San Diego, CA 92126 Tel: (858) 621-2630, 888-672-6627 E-mail: larry@anmar.com Web: www.anmar.com Northrop Grumman Space Technology Contact: John Billingsley One Space Park, S2746 Redondo Beach, CA 90278 Tel: (310) 812-4679 Fax: (310) 814-8797 E-mail: john.billingsley@ngc.com Web: www.st.northropgrumman.com/emc Lockheed Martin Technical Operations Contact: Garland Judd P.O. Box 179 MS P9682 Denver, CO 80201 Tel: (303) 971-9076 Fax: (303) 971-5635 E-mail: garland.c.judd@lmco.com Essco Calibration Laboratory Contact: Michael Walsh 14 Alpha Road Chelmsford, MA 01824 Tel: (800) 325-2201 Fax: (978) 256-1331 E-mail: mwalsh@esscolab.com Web: www.esscolab.com Canada Staveley Services Canada Inc. Contact: Steve Gerassimou 916 Gateway Burlington, ON L7L 5K7 Tel: 1-905-632-5869 or 1-800-897-0067 Fax: 1-905-632-3741 E-mail: steve.gerassimou@staveleycan.com Web: www.staveleycan.com/ EuropeUKDowding & Mills Calibration and Electronics Contacts: Bob Scales (technical), Peter Martin (sales) 60 Wilbury Way Hitchin Hertfordshire SG4 0TA Tel: +44 (0) 1462 421234 Fax: +44 (0) 1462 420012 E-mail: calibration.hitchin@dowdingandmills.com Web: www.dowdingandmills.com Ireland Calibration Specialists Ltd. Contact: Tony O'Marav Holland Rd., National Technology Pk., Castletroy, Limerick. Ireland Tel: +353 (0)61 330333 Fax: +353 (0)61 330452 E-mail: Tony.OMara@Feasa.ie Italy Politecnico di Milano Contact: Dr. Marco Caresana Centro per la Qualità di Ateneo (SIT) P.zza Leonardo Da Vinci 32 20133 Milano - Italy Tel: + 39 02 23 99 63 04 Fax: + 39 02 23 99 63 09 E-mail: marco.caresana@polimi.it Switzerland APTOMET AG Messtechnik und Kalibrierung Ostermundigenstrasse 99b CH-3006 Bern Tel: +41 31 934 06 00 Fax: +41 31 934 06 01 Web: www.aptomet.ch E-mail: calibration@aptomet.ch RUAG Electronics Contact: Ernst Ehrler Gersauerstrasse 71 CH-6440 Brunnen Tel: +41 41 825 0420 Fax: +41 41 825 0429 Web: www.ruag.com E-mail: calibration.electronics@ruag.com Germany esz Elektronik-Service GmbH Max-Planck-Str. 16 D-82223 Eichenau Tel: +49-8141-88887-0 Fax: +49-8141-88887-77 E-mail: info@esz-GmbH.de Web: www.esz-gmbh.de Fluke Deutschland GmbH Heinrich-Hertz-Str. 11 34123 Kassel Tel: +49 0180 / 5 23 34 24 Fax: +49 0180 / 5 23 24 33 E-mail: info@de.fluke.nl Web: www.fluke.de Austria ISOCAL Elektronische Geräte GmbH Neufeldweg 265 A-8042 Graz Tel: +43-316-407660 Fax: +43-316-407660-20 E-mail: office@isocal.at Web: www.isocal.at Sweden Kitron Development AB Contact: Christian Klahr Box 1053 551 10 Jönköping Tel +46 36 559 40 00 E-mail: christian.klahr@kitron.com Web: www.kitron.com Asia/PacificChinaShanghai Institute of Measurement and Testing Technology 1500 Zhang Heng Road Shanghai, China, 201203 Tel: 021-38839800-32210 Mobile: 13901856443 Fax: 8621-50798601 E-mail: zhujp@simt.com.cn Web: www.simt.com.cn Taiwan Electronics Testing Center Address1: (TAOY UAN) No.8,LANE 29,WEN-MING RD. LO-SHAN TSUN KUI-SHAN HSIANG TAOY UAN HSIEN 333,TAIWAN,R.O.C. Address2: (HSINCHU) 2F-5,NO.47,PARK AVENUE 2 SCIENCE-BASED INDUSTRIAL PARK v HSINCHU,TAIWAN,R.O.C. Tel: (TAOYUAN) 886-3-3280026-259 or (HSINCHU) 886-3-5798806 Fax: (TAOYUAN) 886-3-3962548 or (HSINCHU) 886-3-5798805 E-mail: B00@etc.org.tw Web: www.etc.org.tw |
