Diaphragm vacuum pumps
A range of diaphragm vacuum pumps use a dynamic mass-balancing mechanism. This feature of the Model N843 and N880 pumps instantly and automatically compensates for out-of-balance conditions caused by various force loads of gas pressure. This allows smooth running characteristics over the entire operating range. The pumps are especially suitable for use as vacuum roughing pumps used to pump down turbo-molecular pumps. KNF Neuberger Inc., 2 Black Forest Rd., Trenton, NJ 08691.
Micropumps are designed to provide the performance of larger pumps while maintaining a miniature size. Although they are only 1.6 cu in. in total volume, the Model AA pumps provide flow rates of up to 2.7 L/min, pressures up to 9 psig, and vacuums up to 16 in.Hg. Applications include blood pressure monitoring, medicine delivery systems, and air monitoring devices. Sensidyne, 16333 Bay Vista Dr., Clearwater, FL 33760.
Varistaltic tubing pumps
Specially designed for a variety of liquid-handling needs, a line of varistaltic tubing pumps are microprocessor controlled and programmable to accommodate flow rates in a 0.15-2600 ml/hr or 1-6500 ml/min range. The Compulab 3 units can be used as continuous pumps, preset volume dispensers, or combination dilutor/dispensers. Their microprocessor-based controller features a user-friendly, menu-driven program that is accessed from an 80-character backlit keypad and display. The controller also has the ability to change pump speeds and dispensed volumes on the fly while the pumps are in operation. Barnant Co., 28W092 Commercial Ave., Barrington, IL 60010.
Liquid diaphragm pump
A value-priced liquid diaphragm pump is designed with a minimum number of moving parts for added dependability. It can be specified with FDA- or NSF-compliant materials and is available in Carilon, a Shell Chemical Co. thermoplastic with good chemical properties. The pump is self-priming and transfers fluids approaching the viscosity of 90-wt gear oil. Maximum output pressure is 20 psi, and maximum flow is 20 gal/min. Smart Products Inc., 1710 Ringwood Ave., San Jose, CA 95131.
Miniature peristaltic pumps
Miniature peristaltic pumps deliver 0.0003 to 22 ml/min. The Model P625 pumps measure only 1.1 x 1.3 x 2.4 in. Removable, sterilizable tube sets come in a range of materials and sizes, including new formulations with expanded chemical compatibility. Typical operating currents are less than 30 mA, making the pumps suitable for battery power. Speed control circuitry is included. Instech Laboratories Inc., 5209 Militia Hill Rd., Plymouth Meeting, PA 19462-1216.
Fitted with a brushless dc motor and advanced materials, a diaphragm pump is engineered for 10,000 hours of service, 80°C environments, and continuous duty. Applications include medical devices and analytical instruments. The compact pump is designed to be optimized for specific OEM applications. Specifications include flows to 8 L/min, pressure to 30 psi, and vacuum to 20 in.Hg. Hargraves Technology Corp., 116 Gasoline Alley, Ste. 113, Mooresville, NC 28117.
Miniature dispense pumps
Suitable for use in automated clinical instruments, chemically inert dispense pumps are available in both preset (50 µl) and variable-volume models. The pumps offer size and weight savings over conventional syringe and peristaltic pumps, according to their manufacturer. Variable-volume pumps are available in 50-, 250-, and 750- µl configurations, dispensing in 0.1-, 0.5-, and 1.5- µl increments, respectively. Power consumption for all units is less than 2.5 W. The Lee Co., PO Box 424, Westbrook, CT 06498.
Modular digital pump
Device manufacturers can design smaller and lighter instruments using a modular digital pump. The XP 3000 module stands only 5 in. and weighs only 2.5 lb. It automates pipetting, diluting, and dispensing with precision over a wide range of speeds using a variety of syringe sizes. The unit communicates through RS-232, RS-485, or CAN protocol and operates from a single 24-V-dc power supply. Cavro Scientific Instruments Inc., 242 Humboldt Ct., Sunnyvale, CA 94089.