493 LABORATORY EQUIPMENT AND ACCESSORIES: BIOCHEMISTRY, CHEMISTRY, ENVIRONMENTAL SCIENCE, ETC. 49304 * Air Quality Monitoring Equipment and Accessories 49306 * Baths, Constant Temperature (Hot or Cold): Recirculating, Shaking, etc. 49308 * Biochemical Research Equipment: DNA Synthesizers, Enzyme Analyzers, Respirometers, etc. 49309 * Chemical Analysis Systems, Automated: Ion-Sensing Electrode, Micro-Kjeldahl, Titration, etc. 49310 * Chemical Reactors: High-Pressure (Autoclaves), Catalytic, Fluid-Bed, Photochemical, etc. 49311 * Chromatographs, Gas 49312 * Chromatographs, Liquid: High-Performance (HPLC), Preparative, etc.,and Major Accessories: Absorbance/Fluorescence Detectors and Monitors, etc. 49314 * Combustion Analysis Equipment, Automatic (For Carbon, Nitrogen, Sulfur, etc.) 49316 * Densitometers, Scanning (Gel or Plate Scanners) 49317 * Desorber 49324 * Electrophoresis Equipment: Electrofocussing Cells, Gel Driers and Slicers, Power Supplies, etc. 49330 * Evaporators, Analytical (Air or Nitrogen Jet) 49332 * Evaporators, Vacuum: Flash, Rotating, etc. 49335 * Fluorometers and Spectrofluorometers 49338 * Freeze-Drying and Critical-Point Drying Apparatus 49342 * Gas Analysis Equipment (For CO2 Oxygen, etc., in Gas Mixtures) 49344 * Gas Generating and Purifying Equipment: Hydrogen, Oxygen, Ozone, Pure Air, etc. 49350 * Osmometers 49351 * Photoionization Analyzer and Lamps 49352 * Photometers, Flame 49354 * Photometers, Photoelectric (Colorimeters, Transmittance) 49358 * Polarimeters 49360 * Polarographs 49362 * Sample Collecting, Diluting and Multiple Dispensing Apparatus, Automatic: Pipetting Machines, etc. 49363 * Sample Concentrators (For Multiple Samples), Vacuum Type 49369 * Spectrometers, Emission: Argon Plasma and Conventional 49373 * Spectrophotometers, Atomic Absorption 49375 * Spectrophotometers, Infrared 49377 * Spectrophotometers, Ultraviolet and Visible 49380 * Tensiometers (For Surface Tension Measurements) 49384 * Tissue Disrupting, Grinding, and Homogenizing Equipment: Frozen Tissue Pulverizers, Ultrasonic Cell Disrupters, etc. 49392 * Vacuum Still: Short Path, Spinning Band, etc. 49396 * Water Quality Monitoring Equipment: BOD Analyzers, Turbidimeters, Well Samplers, etc.