6
Briefs
Channel Recorders
Sheet Resistivity Measurements of Chemically Modified Electrodes by Four-Point Probe Method 1639
• U p t o 6 c o n t i n u o u s l y overlapping r e c o r d s • E l e c t r o n i c linearization for direct recording in e n g i n e e r i n g units • Plug-in amplifiers for e a s y s p a n c h a n g e •Color c o d e d linear ribbon e a s i l y read at a d i s t a n c e
indicators
• High p r e c i s i o n and reliability laboratory and industrial u s e
O p e r a t i o n a l versatility is e n h a n c e d by bold, clear, color c o o r d i n a t e d linear ribbon s c a l e i n d i c a t o r s t h a t allow o b s e r v a t i o n of p e n position at a d i s t a n c e . A w i d e s e l e c t i o n of c h a r t s p e e d s p e r m i t s c h a r t life u p t o 2000 h o u r s . O p t i o n s i n c l u d e 10 s p e e d e l e c t r o n i c c h a r t drive, event marker, individual c h a n n e l high/low a l a r m s a n d fan fold c h a r t s . Call or write for free product guide.
EI
Chessell Recording
Aids for Analytical Chemists
for
C h e s s e l l Model 320 p o t e n t i o m e t r i c r e c o r d e r s provide 6 c h a n n e l c o n t i n u o u s , fully overlapping r e c o r d s a c r o s s 250 m m (10 i n c h e s ) of calibrated chart width. All i n p u t s a r e electronically linearized a n d r e c o r d e d a s linear f u n c t i o n s for e a s y interpretation. Direct m e a s u r e m e n t of AC or DC electrical p a r a m e t e r s is p o s s i b l e by u s e of plug-in m o d u l a r input amplifiers which provide flexibility for quick s p a n c h a n g e s . No calibration is required. S t a c k e d p e n t r a y s a n d plug-in drive P C B ' s permit e a s y field e x p a n s i o n u p t o 6 c h a n nels.
Data Collection
Vakula S. Srinivasan* and Walter J. Lamb, Department of Chemistry, Bowling Green State University, Bowling Green, Ohio 43403 Anal. Chem., 49 (1977)
A Eurotherm International Company
Systems
Isaac N e w t o n Center, R e s t o n , VA. 2 2 0 9 0 T e l e p h o n e : (703) 471-4830 · Telex: 8 9 9 4 4 9
Photographic Techniques for Fluorescent Spots on Thin-Layer Chromatographic Plates 1640 P. W. Rulon* and M. J. Cardone, Norwich Pharmacal Company, Norwich, N.Y. 13815 Anal. Chem., 49 (1977) Determination of Mercury in Edible Oils by Combustion and Atomic Absorption Spectrophotometry
1641
Wei-Chong Tsai and Lih- Jiuan Shiau, Pood Industry Research and Development Institute, P.O. Box 246, Hsinchu, Taiwan, Republic of China Anal. Chem., 49 (1977) Dry Ashing of Animal Tissues for Atomic Absorption Spectrometric Determination of Zinc, Copper, Cadmium, Lead, Iron, Manganese, Magnesium, and Calcium 1644 E. E. Menden, D. Brockman, H, Choudhury, and H. G. Petering,* Kettering Laboratory, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267 Anal. Chem., 49 (1977) Small Volume, High Performance Cell for Nonaqueous Spectroelectrochemistry 1646 Fred M. Hawkridge,* Department of Chemistry, Virginia Commonwealth University, Richmond, Va. 23284, and Jeanne E. Pemberton and Henry N. Blount,* Brown Chemical Laboratory, The University of Delaware, Newark, Del. 19711 Anal. Chem., 49 (1977) Correction. Studies on the Mechanism of Atom Formation in Graphite Furnace Atomic Absorption Spectrometry 1647 R. E. Sturgeon, C. L. Chakrabarti, and C. H. Langford Correction. Gel Permeation Chromatography of Low Molecular Weight Materials with High Efficiency Columns 1647 Anoop Krishen and Ralph G. Tucker Correction. Determination of Thorium and Uranium in Ores and Mill Tailings by Alpha Spectrometry 1648 C. W. Sill
CIRCLE 4 0 ON READER SERVICE CARD
854 A · ANALYTICAL CHEMISTRY, VOL. 49, NO. 11, SEPTEMBER 1977
