| Author(s): |
George P. Eppeldauer; Howard W. Yoon; Yuqin Zong; Thomas C. Larason; Allan W. Smith; M. Racz; |
| Title: |
Radiometer standard for absolute responsivity calibrations from 950 nm to 1650 nm with 0.05% (k = 2) uncertainty |
| Published: |
June 02, 2009 |
| Abstract: |
A sphere-input transfer-standard detector has been developed to calibrate detectors and radiometers for absolute spectral power, irradiance, and radiance responsivity in the near-IR range with uncertainties similar to those of silicon trap-detector calibrations. The new near-IR reference detector is utilized at the SIRCUS which is the reference calibration facility of NIST for absolute responsivity. The transfer-standard sphere-detector converts the radiant-power scale of the primary-standard cryogenic-radiometer into an irradiance responsivity scale using a tilted input aperture and four symmetrically positioned InGaAs detectors around the sphere-axis and the incident beam-spot. The low conversion uncertainty is the result of a spatial non-uniformity of responsivity of less than 0.05 %. The deviation of the angular responsivity from the cosine function is about 0.03 % in a five-degree angular range. With the new reference detector, a thermodynamic temperature uncertainty of 10 mK (k=2) can be achieved at 157 oC of the In fixed point blackbody. |
| Citation: |
Metrologia |
| Volume: |
46 |
| Pages: |
pp. S139 - S145 |
| Keywords: |
irradiance; near-infrared; radiant power; reference detector; spectral responsivity; transfer standard |
| Research Areas: |
Metrology |
| PDF version: |
 Click here to retrieve PDF version of paper (222KB) |
