NIST Photometric Calibration Services

As of January 2006

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The information of all NIST calibration services on optical radiation is available at the webpage of NIST Technology Services. The information below are further details on photometric calibration services provided by the Optical Sensor Group.

List of Services
Test No.		Items
37010C		Luminous Intensity and Color Temperature Standard Lamps
37020S		Special Tests for Luminous Intensity and Color Temperature of Submitted Lamps
37030C		Color Temperature Standard Lamps
37040C		Each Additional Color Temperature for 37030C
37050S		Special Tests for Color Temperature of Submitted Lamps
37060S		Special Tests for Total Luminous Flux of Submitted Incandescent Lamps and Fluorescent Lamps
37070C		Opal Glass Luminance Coefficient Standards
37080S		Special Tests for Submitted Luminance Sources and Transmitting Diffusers
37090S		Special Tests for Photometers, Illuminance meters, and Luminance meters
37100S		Special Photometric Tests
37110S		Special Tests for Flashing-light photometers
37120S		Special Tests for Color Measuring Instruments for Displays
37130S		Special Tests for Luminous Intensity and Luminous Flux of LEDs
Test numbers ending with C are services in which NIST provides calibrated artifacts. Test numbers ending with S are services in which NIST calibrate artifacts submitted by the customers.

FEE Schedule and Ordering information: Published fees and typical fees of these services are listed.

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Description of Services

37010C Luminous Intensity and Color Temperature Standard Lamps

NIST will issue to the customer 1000 W modified FEL quartz halogen lamps calibrated for luminous intensity (candela) and color temperature (kelvin). These lamps have a double coil filament with a clear bulb, and are potted on a medium bipost base. The lamps are operated at approximately 7 A / 85 V DC, at a color temperature of 2856 K (CIE* Illuminant A). The relative expanded uncertainty (k=2)** of the luminous intensity of these lamps is 0.6 %, and that of the color temperature is 8 K at 2856 K.

37020S Special Tests for Luminous Intensity and Color Temperature of Submitted Lamps

NIST will calibrate the luminous intensity and color temperature of incandescent lamps with a medium bipost base submitted by customers. The inside frosted lamps, the airway beacon lamps, and the 1000 W FEL lamps previously issued by NIST can be submitted for recalibration. Customers can specify either the lamp current or the color temperature of the lamp (normally 2856 K) for calibration. The uncertainty of the luminous intensity of these lamps is typically 0.6 %, and that of the color temperature is 8 K at 2856 K, depending on the reproducibility of test lamps.

37030C Color Temperature Standard Lamps

NIST will issue to the customer 1000 W modified FEL quartz halogen lamps as described in 37010C calibrated for color temperature. The lamps are normally calibrated for a color temperature of 2856 K. The uncertainty of the color temperature of these lamps is 8 K at 2856 K.

37040S Each Additional Color Temperature for 37030C

The color temperature standard lamps requested for 37030C can be calibrated for additional color temperature points in a range from 2000 K to 3200 K. The uncertainty of this calibration is 4 K to 11 K in a range from 2000 K to 3200 K.

37050S Special Tests for Color Temperature of Submitted Lamps

NIST will calibrate the color temperature of incandescent lamps with a medium bipost base submitted by customers. The inside frosted lamps, the airway beacon lamps, and the 1000 W FEL lamps previously issued by NIST can be submitted for recalibration.

37060S Special Tests for Total Luminous Flux of Submitted Incandescent lamps and Fluorescent Lamps

NIST will calibrate the total luminous flux (lumen) of incandescent lamps and fluorescent lamps submitted by customers. The standard lamps previously issued by NIST can be submitted for recalibration. Miniature lamps may also be accepted. Customers should contact NIST before submitting lamps. The uncertainty of the calibration is typically 0.8 % for incandescent lamps and 2.0 % for fluorescent lamps, depending on the reproducibility of test lamps.

37070C Opal Glass Luminance Coefficient Standards

NIST will issue flashed opal glass plates, 51 mm x 51 mm, calibrated for luminance coefficient (ratio of luminance/illuminance, unit: sr^-1) for CIE Illuminant A (2856 K source). The glass plates, masked with a circular aperture of 25 mm in diameter, are calibrated within a circular area of 1 cm in diameter in the center of the aperture. The uncertainty of this calibration is 0.5 %.

37080S Special Tests for Submitted Luminance Sources and Transmitting Diffusers

NIST will calibrate luminance (cd/m²) of submitted sources or luminance coefficient (sr^-1) of submitted transmitting diffusers including opal glass previously issued by NIST. Customers should contact NIST before sending sources or diffusers. The uncertainty of the luminance calibration is typically 0.7 %.

37090S Special Tests for Submitted Photometers, Illuminance Meters, and Luminance Meters

NIST will calibrate photometers, illuminance meters, or luminance meters submitted by customers. Calibration is normally made with the CIE illuminance A (2856 K incandescent source) in a range from 30 lx to 3000 lx for illuminance and 40 cd/m² to 4000 cd/m² for luminance. The uncertainty of calibration is typically 0.5 % for illuminance and 0.7 % for luminance at normal levels, which will increase at lower levels. As an option, NIST can measure the relative spectral responsivity of submitted instruments and calculate spectral mismatch correction factors for a source of known spectral power distribution. Illuminance calibrations in a range from 0.1 lx to 100 klx can also be accepted under a special arrangement.

37100S Special Photometric Tests

NIST can provide special tests for sources, detectors, and photometric instruments other than those stated above under limited conditions, with special arrangements of NIST facility. Customers should contact NIST for consultation.

37110S Special Tests for Submitted Flashing-Light Photometers

NIST will calibrate submitted flashing-light photometers to measure integrated illuminance (lx · s) or effective intensity [cd]. Calibration is normally performed with white light (∼ 6500 K) from a xenon strobe light in the range of 1 lx · s to 100 x · s and with red light using an Aviation Red filter. The uncertainty of calibration is ∼ 1% or larger depending on the performance of the instrument under test.

37120S Special Tests for Color Measuring Instruments for Displays

NIST will calibrate submitted colorimeters or spectroradiometers for chromaticity coordinates (x,y) of several colors of a display. The instrument under test will be calibrated against a NIST reference spectroradiometer, using a standard CRT display or and LCD, or any other display submitted by the customer. The calibration will be performed for the primary colors (red, green, and blue) plus white of the display, and a correction matrix for the Four-Color Method will be provided, which can be used to correct the errors for any other colors of the display measured with the test instrument. The expanded uncertainty (k=2) of the calibration is typically 0.001 to 0.002 in (x,y) depending on the color and display type.

37130S Special Tests for Luminous Intensity and Luminous Flux of LEDs

NIST will calibrate submitted Light Emitting Diodes (LEDs) for luminous intensity (CIE Averaged Intensity A and B in candela) and/or total luminous flux in lumen. For luminous intensity, 5-mm epoxy type or other LEDs that have an alignment fixture can be accepted. For luminous flux, LEDs having luminous flux higher than 0.1 lm can be accepted. Test LEDs are operated with a specified current at ambient temperature of approximately 25 °C. The relative expanded uncertainties (k=2) of the calibrations are typically 1 % to 3 % for luminous intensity and 1 % to 2 % for total luminous flux, depending on the color and reporducibility of the LEDs. Further calibration capabilities are under development.

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* Commission Internationale de l'Éclairage (Int'l Commission on Illumination).

** All the uncertainty values are stated in expanded uncertainty with a coverage factor k=2.

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References

NIST Measurement Services: Photometric Calibrations (7.66MB) ,
Y. Ohno,
NIST Special Publcation 250-37 (1997)

"LED Photometric Calibrations at the National Institute of Standards and Technology and Future Measurement Needs of LEDs," (618 kB) 
C.C. Miller, Y. Zong, and Y.Ohno,
Proc. SPIE Fourth Int'l Conf. Solid State Lighting, Denver, CO, August 2004, 5530, 69-79 (2004).

"NIST Colorimetric Calibration Facility for Displays - Part 2," (101 kB) 
F. Manoocheri, S.W. Brown, and Y. Ohno,
Society for Information Displays, SID 01 DIGEST, 330-333 (2001).

"Establishment of the NIST Flashing-Light Photometric Unit," (91 kB) 
Y. Ohno and Y. Zong,
Proc. SPIE 3140, Photometric Engineering of Sources and Systems, 2-11 (1997).

"High Illuminance Calibration Facility and Procedures," (84 kB) 
Y. Ohno,
J. Illum. Eng. Soc. 27(2), 132-140 (1998).

"Detector-Based Integrating Sphere Photometry," (160 kB) 
Y. Ohno and Y. Zong,
Proc. 24th Session of the CIE 1(1), 155-160 (1999).

"Detector-Based Luminous Flux Calibration Using the Absolute Integrating-Sphere Method,"  (501 kB) 
Y. Ohno,
Metrologia 35(4), 473-478 (1998).

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