MCI Automatic Moisture Meter. Reliable, Fast and Easy. Incorporates coulometry principle applied to Karl Fischer titration. Operation is full-automatic. Measuring time is shortened. Accuracy is within 5//g for 10^g—lmg H 2 0 and within 0.5% for 1—30mg H 2 0 . Wide-range applications include measurement of ultra-trace water content in liquids, solids and gases. Range: 10>g—30mg H2O. An optional water vaporizer for speedy and accurate measurement of water content in plastics, grain, etc.
Printer
(optional)
CA-02 Moisture Meter w i t h Printer
Focus against a more conventional, though less convenient, technique—atomic absorption (AA) spectrometry. He found the AA measurements to be in substantial agreement with the gamma-ray transmission values. "Our approach is unique," says Schneider, "in that it provides a quantitative measurement of the converter's lead content while still being portable and simple to operate. A measurement can be made in one minute by inexperienced people in the field, without removing catalyst samples from the converter for chemical analysis." The Environmental Protection Agency is currently evaluating a lightweight battery-operated lead analyzer commercially manufactured to GM's specifications by Overhoff & Associates, Inc., according to the GM magazine Search, in which development of the transmission gauge was announced.
MITSUBISHI CHEMICAL INDUSTRIES LIMITED Instruments Dept., Mitsubishi Bidg., 5-2, Marunouchi 2-chome, Chiyoda-ku, Tokyo, 100 Japan Telex: J24901 Cable Address: KASEICO TOKYO CIRCLE 141 ON READER SERVICE CARD
Con*01 1
005 c ' S O L I D STATE C I R C U L A T O R S 81 B A T H S
For precision, safety, reliability, choose Tempunit® circulators and baths. Quality units w i t h many exclusive features: 1. Adjustable temperature selection. 6. 7. 2 Three preset temperature 8 selections. 9. 3 Stainless steel construction. 10. 4 Stirrer or pump. 5. Ultra quiet motor.
Overheat protection. Electronic control. Large temperature dial Low level cutout. Setting dial lock.
Call or write Techne. Inc., 3 7 0 0 Brunswick Pike, Princeton, IMJ 0 8 5 4 0 , (609)452-9275.
T e c h n e BATHS & CIRCULATORS CIRCLE 203 ON READER SERVICE CARD 956 A • ANALYTICAL CHEMISTRY, VOL. 53, NO. 8, JULY 1981
Denver Haze Study General Motors (GM) Research Laboratories also recently completed a detailed analysis of Denver's "brown cloud" phenomenon. The phenomenon, characterized by decreased visibility, occurs when weather conditions prevent adequate mixing of atmospheric air layers, thus trapping local pollutants. "We identified the chemical composition of essentially all the particulate mass," said George Wolff, head of a team of GM researchers that conducted the study. "No one ever came close to doing that before for any urban area." GM researchers estimated that motor vehicles contributed 27% to the visibility reduction in Denver during the period of their study, Nov. 8 to Dec. 20, 1978. Wood-burning caused 18%, and nonvehicular combustion of fossil fuels caused 46%, of the visibility reduction. Denver's brown cloud phenomenon is caused by a temperature inversion. Normally, air at ground level is heated by the sun, decreasing its density and causing it to rise. As it rises, pollutants generated at ground level are carried up and away. But in Denver, cold air drains overnight from the surrounding mountains and becomes trapped
