Abstract: An electrically powered forced air heater includes six triangular PTC heating elements co-planarly disposed within a circular shroud with a apex of each element being disposed adjacent a common central point and the sides of the six PTC heating elements which are opposite the aforesaid apexes forming a hexagon. The area collectively occupied by the six PTC heating elements is greater than 78% of the cross sectional area of the circular shroud. The PTC heating elements are provided with a multiplicity of air flow holes therethrough and an electric fan is arranged to force air through the holes without interference with the rotational component of the fan-forced air vortex before the fan forced air strikes the PTC heating elements.

Abstract: A small magnet for stirring a cuvette is disclosed and the means by which the small magnet is rotated within the cuvette without any mechanical connection. Thus solutions within the cuvette may be measured and monitored, if necessary, in the total absence of daylight which reduces the impact of noise on sensors commonly used when spectrophotometric and spectroflourometric studies of solutions within the cuvette are performed.