| 摘要 |
For the automatic color change in a paint, in an automatic paint spray system for series working, the electrical conductivity is measured for a mixture of paint and rinsing agent within the return channel before being flushed out. The rinsing action is halted while the difference between the two conductivity values is at or below a preset level. The preset conductivity difference value is established empirically for each new paint color, and for each change from an old paint to a new paint color. The rinsing agent has a single constituent or has a number of constituent components, using deionized water and /or glycol as ethylene glycol or butyl glycol. The salinity of the rinsing agent is measured. The automatic painting system uses a water paint. An Independent claim is included for a paint spray assembly, using electrically conductive paint and especially a water paint, with a color change unit (1), a spray unit (7), a channel (6) linking the color change and spray units, and a sensor (10) to measure the electrical conductivity of the medium flowing through the channel (6) or the return channel (8). A second sensor (11) is in the channel (12) which delivers the rinsing medium. An evaluation system gives the difference between the two measured conductivities. Preferred Features: The sensors (10,11) have a temp. and conductivity sensor. A system compensates for the temp. of the conductivity measurements.
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