An optical method for direct determination of the radiometric aperture area at high accuracy

A. Lassila, P. Toivanen, E. Ikonen

Research output: Contribution to journalArticleScientificpeer-review

33 Citations (Scopus)

Abstract

An optical method for calibration of the aperture area is described and studied both theoretically and experimentally. A spatially uniform, known irradiance is formed over the aperture by overlapping identical, parallel laser beams centred at constant spacing in an orthogonal lattice. The ratio of the throughput power and irradiance gives the area of the aperture. The method has several advantages compared with previous methods: it measures the area of the aperture directly, the shape of the aperture is not limited to a circle, it is relatively inexpensive to establish, it does not damage the edges of the aperture and the calibration set-up is similar to that for the actual use of the aperture. It is estimated that the relative standard uncertainty is 1.6 × 10-4 in calibration of a circular 3 mm diameter aperture. The results that the present method gave for one aperture have been compared with the result of a mechanical calibration at the National Physical Laboratory (UK). The relative difference between the results was 2.4 × 10-4, with a combined standard uncertainty of 2.5 × 10-4.

Original languageEnglish
Pages (from-to)973-977
Number of pages5
JournalMeasurement Science and Technology
Volume8
Issue number9
DOIs
Publication statusPublished - 1 Jan 1997
MoE publication typeA1 Journal article-refereed

Fingerprint

High Accuracy
Calibration
apertures
optics
Irradiance
Uncertainty
Laser Beam
Spacing
Laser beams
Overlapping
irradiance
Circle
Throughput
Damage
spacing
laser beams
damage
Standards

Cite this

@article{c0d243bf8fd64bb5bc5b07e5f21757f1,
title = "An optical method for direct determination of the radiometric aperture area at high accuracy",
abstract = "An optical method for calibration of the aperture area is described and studied both theoretically and experimentally. A spatially uniform, known irradiance is formed over the aperture by overlapping identical, parallel laser beams centred at constant spacing in an orthogonal lattice. The ratio of the throughput power and irradiance gives the area of the aperture. The method has several advantages compared with previous methods: it measures the area of the aperture directly, the shape of the aperture is not limited to a circle, it is relatively inexpensive to establish, it does not damage the edges of the aperture and the calibration set-up is similar to that for the actual use of the aperture. It is estimated that the relative standard uncertainty is 1.6 × 10-4 in calibration of a circular 3 mm diameter aperture. The results that the present method gave for one aperture have been compared with the result of a mechanical calibration at the National Physical Laboratory (UK). The relative difference between the results was 2.4 × 10-4, with a combined standard uncertainty of 2.5 × 10-4.",
author = "A. Lassila and P. Toivanen and E. Ikonen",
year = "1997",
month = "1",
day = "1",
doi = "10.1088/0957-0233/8/9/003",
language = "English",
volume = "8",
pages = "973--977",
journal = "Measurement Science and Technology",
issn = "0957-0233",
publisher = "Institute of Physics IOP",
number = "9",

}

An optical method for direct determination of the radiometric aperture area at high accuracy. / Lassila, A.; Toivanen, P.; Ikonen, E.

In: Measurement Science and Technology, Vol. 8, No. 9, 01.01.1997, p. 973-977.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - An optical method for direct determination of the radiometric aperture area at high accuracy

AU - Lassila, A.

AU - Toivanen, P.

AU - Ikonen, E.

PY - 1997/1/1

Y1 - 1997/1/1

N2 - An optical method for calibration of the aperture area is described and studied both theoretically and experimentally. A spatially uniform, known irradiance is formed over the aperture by overlapping identical, parallel laser beams centred at constant spacing in an orthogonal lattice. The ratio of the throughput power and irradiance gives the area of the aperture. The method has several advantages compared with previous methods: it measures the area of the aperture directly, the shape of the aperture is not limited to a circle, it is relatively inexpensive to establish, it does not damage the edges of the aperture and the calibration set-up is similar to that for the actual use of the aperture. It is estimated that the relative standard uncertainty is 1.6 × 10-4 in calibration of a circular 3 mm diameter aperture. The results that the present method gave for one aperture have been compared with the result of a mechanical calibration at the National Physical Laboratory (UK). The relative difference between the results was 2.4 × 10-4, with a combined standard uncertainty of 2.5 × 10-4.

AB - An optical method for calibration of the aperture area is described and studied both theoretically and experimentally. A spatially uniform, known irradiance is formed over the aperture by overlapping identical, parallel laser beams centred at constant spacing in an orthogonal lattice. The ratio of the throughput power and irradiance gives the area of the aperture. The method has several advantages compared with previous methods: it measures the area of the aperture directly, the shape of the aperture is not limited to a circle, it is relatively inexpensive to establish, it does not damage the edges of the aperture and the calibration set-up is similar to that for the actual use of the aperture. It is estimated that the relative standard uncertainty is 1.6 × 10-4 in calibration of a circular 3 mm diameter aperture. The results that the present method gave for one aperture have been compared with the result of a mechanical calibration at the National Physical Laboratory (UK). The relative difference between the results was 2.4 × 10-4, with a combined standard uncertainty of 2.5 × 10-4.

UR - http://www.scopus.com/inward/record.url?scp=0031235698&partnerID=8YFLogxK

U2 - 10.1088/0957-0233/8/9/003

DO - 10.1088/0957-0233/8/9/003

M3 - Article

AN - SCOPUS:0031235698

VL - 8

SP - 973

EP - 977

JO - Measurement Science and Technology

JF - Measurement Science and Technology

SN - 0957-0233

IS - 9

ER -