A new portable centrifugal analyzer with expanded versatility.

Developments in solid-state electronics have resulted in the fabrication of a prototype portable instrument with expanded analytical versatility and the capability to operate from 110 V ac or a rechargeable battery pack. The analyzer, contained in an 18 x 11 x 12-in. box and weighing 55 lb, utilizes a self-contained microprocessor to control a number of analyzer functions as well as to perform data acquisition and analysis. Hardcopy output is produced by an integral thermal printer. A number of analysis options are available including determination of reaction rate by linear regression analysis. Temperature control is maintained at one of three set points (25, 30, or 37/sup 0/C) by means of a thermoelectric heat pump located in the rotor holder. A clutch-brake assembly incorporated in the rotor drive system enables the rotor to be accelerated to 80 percent of run speed within 100 ms. Utilization of a parallel-channel rotor and a high-resolution, 2 MHz clock enables reactions to be monitored within 100 ms of solution transfer. A maximum of 99 observations may be acquired at variable intervals, the minimum being 1 observation per revolution at 4000 rpm (one observation consists of measurements of dark current and transmission or fluorescence signals frommore » 17 cuvets). The drive system, rotor speed, and the clutch-brake are controlled by the microprocessor and automatically synchronized with data acquisition. Other analyzer operations currently under control of the microprocessor include the selection of preamplifier gain, transmission filters, and primary and secondary filters for fluorescence. The system is described and its various analytical capabilities are evaluated.« less