Electronic displays and computer systems offer numerous advantages for clinical vision testing. Laboratory and clinical measurements of various functions and in particular of (letter) contrast sensitivity require accurately calibrated display contrast. In the laboratory this is achieved using expensive light meters. We developed and evaluated a novel method that uses only psychophysical respons...

Electronic displays and computer systems offer numerous advantages for clinical vision testing. Laboratory and clinical measurements of various functions and in particular of (letter) contrast sensitivity require accurately calibrated display contrast. In the laboratory this is achieved using expensive light meters. We developed and evaluated a novel method that uses only psychophysical respons...

LTHOUGH THE FLAME PHOTOMETER jS the method of choice for the determination of serum sodium in most large, well-equipped laboratories, there remains a place for an alternative procedure which can be used in laboratories too small to afford a flame photometer, or which can be carried out by an intern, resident, or general laboratory technician at night or at other times when the photometer operat...

This paper describes a simple, inexpensive transimpedance amplifier (TIA) suitable to convert the fast current pulses delivered by photomultiplier tube of night airglow photometer into the corresponding voltage. Design criteria for the transimpedance amplifier are carefully selected to include low input bias current, offset voltage and noise. The operation of the transimpedance amplifier and th...