Cahn Instruments

Langmuir trough (Cahn Instruments Surface Tension Accessory No. 099-002910-30) in which the film could be rapidly compressed and expanded at a linear rate by means of moving barriers at either end of the balance (Fig. 9). This equipment was redesigned to reduce leaks and to follow a linear rather than sinusoidal cycle. 

Figure 4. Automatic dynamic surface tension balance showing Wilhelmy plate suspended in surface. Photograph supplied by Cahn Instruments, Inc.

Cahn Electrobalance, Cahn Instrument Co., Downey, California. 

Ohaus Corporation lOPeopody St. Bradford, MA 01835-7614 1-800-526-0659 http //www.balances.com Cahn Instruments 5225 Verona Rd. Bldg. 1 Madison WI 53711 (800)244-6305 http //www.cahn.com/... 

E. F. Kondis (Mobil Research Development Corp., Paulsboro, N. J. 08066) We confirmed some of the trends in nonisothermal results which you report. Our data are in a flow system and hence discount the possibility of heat effects caused by expansion of gas using your Cahn instrument. 

The mass of the deposited polymer on Al-substrate was determined by weighing with a "Cahn Gram Electrobalance" (Cahn Instrument Co., Paramount, California). Infrared spectra of polymers were also recorded, using a Perkln-Elmer Spectrophotometer. 

H2O, n-hexane and cyclohexane sorption capacities of SAPO-31 were determined gravimetrically using a vacuum microbalance (Cahn Instruments, USA). The size and the morphology of the crystals of SAPO-31 were examined using a JEOL (JSM-840 A) scanning electron microscope. The BET surface area was determined using a volumetric adsorption apparatus ( Model Omnisorb lOOCX, Coulter, USA). 

A high-pressure enclosure for the Cahn 1000 electrobalance, for use at pressures up to 1500 psi, is available from Cahn Instruments. The enclosure is machined from two pieces of stainless steel and contains no weld joints. Optional accessories include a reactor and counterweight chambers and O-ring sealed couplings. 

A gravimetric method was used to deteimine the C02 adsorbing capacities of the prepared hydiotalcites. The amount of sample loaded into the TGA unit (C-1100, CAHN INSTRUMENTS. INC.) was 6S mg. The sample was pretreated in flowing Hie at 500 for 3 h. Afto- the temperature was lowered to 450 C, CO2 was introduced to the balance and the weight change was measured. The range of adsorption pressure was between 0 to 1000 mmHjg. 

Most modern TGAs, however, in addition incorporate the principle of electromagnetic balances that have relatively little dependence on vibration (one of the common problems for weight measurements), have high sensitivity, and display little thermal drift. The beam position is monitored by a photodetection scheme. This concept was introduced by Cahn Instruments. As shown in Fig. 2, after taring the sample, the balance is assumed to be in equilibrium. Addition of the sample to the left side of the beam will cause the right side of the beam to be displaced upward. Sufficient current is... 

Cahn Instruments, 5225 Verona Road, Bldg. 1, Madison, WI 53711-4495, USA Cahn ... 

Cahn Instruments (part of THASS) www.thass.net THASS, Thermal Analysis and Surface Solutions GmbH Pfingstweide 21 61169 Friedberg Germany... 

Electrobalance with a radioactive source in the weighing chamber. Such a balance may be obtained from the Cahn Instrument Company (Gram Electro-balance) and has the advantage over more conventional semimicro- and micro-... 

Cahn Instruments Inc., 16207 South Carmenita Road, Cerritos, CA 90723, USA, (213) 926 3378... 

Figure 7. Experimental setup for TGA studies utilizing a Cahn Instruments C-1100 pressure balance.

---