| 摘要 |
PURPOSE:To measure etch solution concentration with high accuracy by monitoring concentration of only ions contained in an etch solution being in use, as selective object ions, in a state where impurities are mixed in dampening water. CONSTITUTION:Dampening water 2 stored in a dampening water tank 1 is sent by a circulating pump 3 via a feed water pipe 5 to a water sump 6 to be lead to a printer roller. The water sump 6 is constituted so as to hold a specified quantity of the dampening water 2. The dampening water 2 which has not been consumed in a printer is circulated to the dampening water tank 1 via a return water pipe 7, circulating pump 3, and a cooler 4. Since the dampening water 2 is thus used in circulation, impurities such as ink and very fine pieces of printing paper are mixed therein. Here, the dampening water 2 in the tank 1 is extracted by using a beaker or the like. A sample of the extracted dampening water 2 is measured for etch solution concentration by using a solution concentration measuring device of which a measuring part is soaked in the sample of water 2. |
