Plug-in IR card A spectrograph card that plugs into a PC incorporates a 256-element thermoelectrically cooled InGaAs array detector. De signed for absorbance, transmittance, fluo rescence, and Raman spectroscopies, it spans the spectral range of 900-1650 nm with 3.5-nm resolution and can acquire spectra in 3 ms. Sample chambers, fiber optic accessories, Raman probes, and light sources are also available. Control Development • 408
Mapping t e m p e r a t u r e and t e x t u r e by microscopy Two tools for SPM, a thermal conduc tivity probe and a software module for characterizing surface hardness and adhesive properties, are designed for use with atomic force or scanning tun neling microscopes. The thermal probe measures the thermal conductivity and surface tem perature of samples. Designed for use in the TMX 2000 series of scanning probe microscopes, the cantilever with its resistive thermal element can be used to acquire thermal images (shown) simultaneously with the to pographic images obtained by AFM or STM. The thermal probe can be used in two modes. As a passive element, its re sistance is monitored as a function of the temperature of compounds on the surface being scanned. Typical applica-
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Capillary viscometry The Automatic Capillary Viscometer is de signed for measurement of kinematic vis cosity in the range of 2-2000 cSt in 60300 s for oils and other liquids. The benchtop modular design can containfrom4 to 16 viscometers and requires only 0.5-1.0 mL of sample. Cannon • 409 Polymer analysis Crystaf Model 100 polymer analyzer per forms structural analysis in linear low-
tions include the identification of hot spots in printed electronic circuits. The probe can also be used in active mode by passing current through it so that it is heated and kept at either constant temperature or constant resistance. The different heat-exchange character istics of the surface components can be used to map them according to their effect on either probe temperature or resistance. This method has been used to characterize the interfaces be tween layers of carbon composite mate rials. Layered Imaging software allows an AFM system to measure cantilever de flection at different locations along the force-distance curve as the probe tip approaches and pulls away from a surface. With the software, the sys tem can acquire 40,000 force-distance curves over an entire surface, mea suring the deflections at a series of dif ferent forces in each separate pixel of surface area. At any constant force, the tip should be deflected by the same amount leaving the surface as it was on its approach if there is no interaction between them. Any adhesion or "give" between the tip and the surface dis torts the reversibility of the process and is reflected in the force-distance curve for that pixel. From the forcedistance curves, the software can map surface hardness or compliance, mag neticfieldsat given distances above the surface, and surface stickiness. TopoMetrix • 4 1 0
density polyethylene, polypropylene, and other semicrystalline polymers by fraction ating them according to the crystallizability of polymers with different morphology or co-monomer content. Model 100 is fully automated and PC controlled with a Lab View for Windows-based user inter face. The software displays flow pattern, temperature, valve operation, and detector readings and archives and exports data to other databases. A compact solid-state IR detector can analyze the short-chain branching distribution offivepolyethyl ene samples simultaneously in < 6 h. Polymer ChAR • 411 Multipass cells Astigmatic multipass optical cell, designed for trace gas monitoring and AOTF di ode laser spectroscopy, provides 100 m of pathlength compressed into a 70-cm long, 3.2-L cell. The astigmatic optical cav ity design causes the beam to travel in a Lissajous pattern thatfillsthe absorption volume more completely than a conven tional multipass configuration does. A smaller cell compresses 36 m of pathlength into a 30-cm, 0.3-Lunit. The cells ac commodate pressures from atmospheric pressure down to a few tenths of a pascal. New Focus B412 Process near-IR FCT Series cross-line sampling systems are designed for near-IR spectroscopy of high-temperature and high-pressure pro cesses such as monitoring hot melt poly mer extrusion. The systems consist of pairs of diametrically opposed fiber-optic coupled probes that are rated at pressures to 5000 psi and temperatures to 300 °C. Fibers that are 0.6 mm in diameter with a 6-mm transmission pathlength have opti cal transmissions of > 25%. Axiom Analytical B413 Luminescence spectroscopy FL/FS900 combined luminescence spec trometer is designed to operate in timecorrelated single-photon counting mode for lifetime measurements and in singlephoton counting mode for steady-state spectral measurement. Edinburgh Instruments 1 4 1 4
Analytical Chemistry, Vol. 67, No. 3, February 1, 1995 141 A
