Evaluation of a Hyperbaric System to be Used in Conjunction with a Fluorometer
NAVAL MEDICAL RESEARCH INST BETHESDA MD
Pagination or Media Count:
A high-pressure chamber that can be used inside the sample chamber of a spectrofluorometer is described and some performance characteristics are presented. The chamber body, constructed of 316 stainless steel, is temperature regulated using resistive heating elements and a microprocessor-based proportional integral derivative controller. The chamber holds a standard 1-sq cm cuvette that indexes with an electromagnetic stirrer. Injection of different solutions into the closed and pressurized 6.8 MPa vessel is accomplished by computer-controlled, low-volume solenoids attached to separate microliter injection ports. Repetitive injections of fluids down to a volume of 7 microliters are possible in the pressurized chamber. Temperature stability of the chamber is or - 0.2 deg C at atmospheric or elevated pressure. However, during the initial phase first 3 min of pressurization, at a compression rate of 0.62 MPamin, a 0.23 deg Cmin increase in temperature occurs. The chamber windows depress the relative intensity of the emitted light by approximately 20 for visible light and 40 for near UV however, total sensitivity of the system is sufficient to accomplish most determinations while maintaining a good signal- to-noise ratio. This system can be used to evaluate the response of several molecular and cellular events during compression and at depth with the use of various fluorometric probes.
- Hydraulic and Pneumatic Equipment