Review of the progress in research, instrumentation, and service activities of the Spectrochemical Analysis Section from July 1970 to June 1971.

Technique for varying the coupling of power from far-infrared gas lasers and the design and construction of these lasers.

Pamphlet issued by the United States National Bureau of Standards containing a list of government pamphlets, reports, and other resources related to the metric system of measurement. It includes a form for ordering materials from the Government Printing Office as well as an illustrated description of everyday conversions for weight, volume, length, and temperature.

Report presenting new measurement techniques used to obtain potential curves, f-values, and kinetic behavior for Hg2. The Hg2 molecule is representative of a class of molecules which have dissociative ground states and bound excited states. It can therefore be used as a prototype of this class of molecules which are of interest as potential new laser candidates. Because of the non-bound ground state, standard absorption spectroscopic techniques cannot be used to obtain the necessary information about the excited states.

Report is a guide to Standard Reference Materials (SRM's) and should be useful to all users of SRM's particularly those in countries developing national measurement systems. It is not intended to be an exhaustive description of the NBS-SRM program, but rather a review of the role SRM's play in the measurement system, how SRM's are certified, and what the certification means. To illustrate the use of SRM's, several selected industries are described in which SRM's have made significant contributions.

Report containing information of general interest to manufacturers and users of liquid-in-glass thermometers. This report supersedes Monograph 90. Instructions explaining how to submit a thermometer to the National Bureau of Standards for calibration are provided, and the techniques and equipment, such as stirred liquid comparison baths, used in the calibration procedures are described. A discussion of important principles of acceptable thermometer design and factors affecting their use is included. Listed are tables of tolerances reflecting good manufacturing practices and reasonably attainable accuracies expected with liquid-in-glass thermometers. The calculation of corrections for the temperature of the emergent stem is given in detail for various types of thermometers and conditions of use.

Report discussing the different bases for determining mass values and instances where these differences may be crucial. The first part is a historical summary of weighing, standards, and the assignment of value; and the interfacing of mass measurements with civilization. The second part discusses in detail the methods of assigning mass values. Ways to convert from values on one basis to values on another basis are discussed.

Report on calculations of hydrogen Stark broadening on the basis of the unified classical path theory which has been extended to include lower state interactions in the final line profile. A detailed comparison with experiments in the density range 10-13-10-17 cm-3 is given.

From Introduction: "This report is a compilation of the MeV Total Neutron Cross Section data measured at the U.S. National Bureau of Standards."

From Introduction: "This paper describes in some detail how Bolovac works, when its structural components are, what are the methods and steps of the procedure in its various major applications, and reasons for its advantages. The emphasis is on applications. Present status at the National Bureau of Standards relating to fabricating the most important component of the Bolovac-the bolometric disk-is briefly pointed out."