Constructing a fish egg counter device

Abstract

We devised a device for precise fish egg counting that incorporated three units electronic, mechanical and water network. In the device, a selector disc (mechanical unit) separates each egg from the batch and injects it into a fluid stream (water network) which is then detected by an infrared interrogator. The electronic detector generates a pulse to counter circuit and then activate the numerical display showing the number of the past eggs. There is also the option of a present system that allows programming number of the eggs that should be counted. The machine will stop when this preset number is reached. The efficiency of all parts were examined with trout eggs with an average diameter of 4 to 5.7mm. In the fish trial, we obtained an undercounting of 16 eggs. After adjustments, the undercounting reached unity. The selector disc was designed in the sizes of 4.5, 5.5 and 6.5mm to allow counting of most egg sizes. The first disc size allowed counting of 9000 eggs per hour. The counting capability increased to eggs per hour when more holes were punched in the disc. It is possible to increase the counting rate using higher velocity of disc rotation, mounting double discs or two detectors with one disc.