انهاك المحلول المظهر .. كتاب التحميض والطبع والتكبير

Developer Exhaustion

If the presenting solution is used repeatedly, the degree of its activity gradually decreases, because the reducing agents are gradually destroyed as a result of the reduction of silver salts (often silver bromide) to metallic silver. The extent of exhaustion of the apparent solution depends on the following factors:
(a) The number of images or the length of the film area that has been shown, so the speed of its completion increases with the increase in the number of these images or films.
(b) The degree of concentration of the solution, so that the diluted solution is subject to rapid exhaustion.
(H) The composition of the solution and the proportions of salts included in its composition. (k) The degree of density of the images that appeared in the solution, as the increase in the density indicates an increase in the duration of the image in the solution, or an increase in the consumption of the active substances contained in the apparent solution. It also indicates an increase in the products of the reduction process that hinder the expression, and thus the rate of exhaustion of the solution increases.
(e) The solution may spoil the appearance if it is exposed to air, as the reducing agent is oxidized by the oxygen of the air.
(f) Some types of solutions may deteriorate, even if they are not used at all, simply because they are not able to remain for a long time.
On page 83, there is an approximate statement of the number of films that may be shown in a basin or with dilute solutions in a tank, or in solutions that lead to general fine particles. We have assumed in this table that the presenting solutions are of fresh composition. The area of ​​the rolled film with images measuring 6 x 9 cm is about 450 cm. The same applies to the 35 mm films that hold 36 images. And if we want to show these flat or wrapped films or sensitive panels one after another, the duration of showing the second film must be increased by 100% over the period specified for showing the first film, and thus the period increases by this percentage in each film over the previous one.