gentecv106

T 418.651.8003 1 888 5GENTEC F 418.651.1174 www.gentec-eo.com info@gentec-eo.com 10 10 Monitors Energy Detectors Power Detectors OEM Detectors Calorimeters Diffractive Optics Beam Diagnostics CalibRaTiOn HOW IT WORKS THE FAQ'S Question Answer Question Answer Question Answer The calibration uncertainty of a commercial detector can never be lower than that of a gold standard calibrated by the NIST Question Answer I bought a detector that carries a ±1% uncertainty. Can you do better? The best uncertainty available is the reference measuring instrument used by the NIST (or other Institute of metrology standards). NIST offers calibration services that enable power meter manufacturers to get their own reference (also called a gold standard) with a typical uncertainty of ±1%. Any detector calibrated against that reference must carry an additional uncertainty, which makes a ±1% detector a physical impossibility. Although my supplier quotes me a speci?c calibration accuracy, they are assuring me that their detector is more accurate than this. As a proof, they claim when comparing their standards to the NIST standard, the discrepancy is around 1%. This suggests that my detector's accuracy is under ±2%. Here, your supplier is quoting repeatability, not accuracy. Please refer to «The Terms» de?ned previously within this section of the Gentec-EO catalog. My detector offers the same calibration uncertainty over its full operating spectrum range and full NIST traceability as well, what about yours? A calibration is always done at a speci?c wavelength (sometimes two). For detectors used at wavelengths other than the calibration wavelength, an additional calibration uncertainty must be added. With Gentec-EO detectors, the Personnal Wavelength Correction TM allows to add only ±1% (also NIST traceable) to the nominal calibration uncertainty when used at any nm step outside the calibration wavelengths. My supplier assures me that he can calibrate my detector at 157 nm with full NIST traceability. Can you also do it? A NIST traceable detector at 157 nm requires a NIST traceable source at that wavelength. The NIST offers standard calorimeter calibrations at certain wavelengths only, and 157 nm is not one of them. You should always ask for a proof of traceability to NIST from your supplier. A calibration is not NIST traceable if it is not done using a NIST reference ? ? ? ?

T 418.651.8003 1 888 5GENTEC F 418.651.1174 www.gentec-eo.com info@gentec-eo.com 11 Monitors Energy Detectors Power Detectors OEM Detectors Calorimeters Diffractive Optics Beam Diagnostics CalibRaTiOn HOW IT WORKS Time to put your reading to the test! THE QUIZ Question 1 Answers What is the best term to describe QUANTITATIVELY the «goodness» of a result? a) Calibration Uncertainty b) Accuracy c) Error d) Precision Question 2 Answers Who calibrates a Gentec-EO detector? a) An outside calibration company b) Gentec-EO only c) Gentec-EO's accredited laboratories d) An outside company using a NIST calibrated standard Question 3 Answers What is the lowest possible calibration uncertainty available on the market (outside NIST)? a) ±1% b) ±2% c) ±2.5% d) ±3% Question 5 Answers What is the main advantage of a detector calibrated by Gentec-EO a) Calibration is done by Gentec-EO's accredited laboratories b) You have a real measure of uncertainty c) You have a NIST calibration value over all the range d) All these answers Answers : 1-a, 2-c, 3-c, 4-d, 5-d. Question 4 Answers What wavelength(s) is(are) part of the NIST calibration wavelengths? a) 157 nm b) 248 nm c) 1064 nm d) b and c are both wavelengths available from NIST