INDUSTRY AND RESEARCH NEWS ***See 2011 NIST Tech Beat article, “Prototype NIST Device Measures Absolute Optical Power in Fiber at Nanowatt Levels,” at www.nist.gov/pml/div686/ radiometer-122011.cfm. Source: NIST Tech Beat, January 24, 2013. individual nanotubes are about 10 nanometers in diameter and 150 micrometers long. By contrast, ordinary cryogenic radiometers use more types of materials and are more difficult to make. They are typically hand assembled using a cavity painted with carbon as the light absorber, an electrical wire as the heater, and a semiconductor as the thermistor. Furthermore, these instruments need to be modeled and characterized extensively to adjust their sensitivity, whereas the equivalent capability in NIST’s mini-radiometer is easily patterned in the silicon. NIST plans to apply for a patent on the chip-scale radiometer. Simple changes such as improved temperature stability are expected to greatly improve device performance. Future research may also address extending the laser power range into the far infrared, and integration of the radiometer into a potential multipurpose “NIST on a chip” device. * N.A. Tomlin, J.H. Lehman. Carbon nanotube electricalsubstitution cryogenic radiometer: initial results. Optics Letters. Vol. 38, No. 2. Jan. 15, 2013. ** See 2010 NIST Tech Beat article, “Extreme Darkness: Carbon Nanotube Forest Covers NIST’s Ultra-dark Detector,” at www.nist.gov/pml/div686/dark_081710.cfm. Image Source: National Institute of Standards and Technology. Credit: Tomlin/NIST. OHMLABSresistorsAD3.10_Layout 1 4/8/10 12:46 PM Page 1 H IGH R ESISTANCE S TANDARDS • • • • • • FULLY GUARDED FOR ANY RATIO BPO OR N TYPE CONNECTORS VERY LOW TCR & VCR STABLE OVER TIME INTERNAL TEMPERATURE SENSOR 17025 ACCREDITED CALIBRATION MODEL 106 107 108 109 110 111 112 113 RESISTANCE 1 MΩ 10 MΩ 100 MΩ 1 GΩ 10 GΩ 100 GΩ 1 TΩ 10 TΩ TCR / VCR <1 <3 < 10 < 15 < 20 < 30 < 50 < 300 / / / / / / / / < < < < < < < < 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 SEE WWW.OHM-LABS.COM FOR SPECIFICATIONS 611 E. CARSON ST. PITTSBURGH, PA 15203 TEL 412-431-0640 FAX 412-431-0649 WWW.OHM-LABS.COM Jan • Feb • Mar 2013 13 Cal Lab: The International Journal of Metrology