Method for ascertaining the content of an ingredient of flux in automatic soldering machines

An apparatus for ascertaining a content of an ingredient of flux in an automatic soldering machine which comprises a soldering machine region (1), a measuring region (2), and an evaluation region (3), the soldering region includes a flux supply container (13), a first pump (16) in a first flux line (6) from said flux supply container to a flux recirculating container (11), a thinner supply container (12), a second pump (15) in a second flux line (5) from said thinner-supply container (12) to said flux recirculating container (11), a fluxer (17), a third pump in a third flux line (4) from said flux recirculating container (11) to said fluxer (17), a fourth flux line (7) from said fluxer (17) to said flux recirculating container (11), said measuring region (2) includes density measuring container (19) which communicates with a bypass line (18) connected to said fourth flux line (7) between said fluxer and said flux recirculating container (11), said density measuring container (19) includes therein a density measuring instrument (20) and a temperature sensor (21), said density measuring container (19) is connected by a fifth flux line (9) with a valve (31) which is also connected with said thinner supply container (12) via a sixth flux line (8), said value (31) is connected with a fourth pump (22) which is connected with a first sample vessel (23), said first sample vessel is connected in series with a second sample vessel (24) which is turn is connected with said density measuring container (19), a first radiation source is positioned juxtaposed said first sample vessel (23) for directing radiation through said first ample vessel onto a first detector (27) which measures and records any radiation passing through said first sample vessel, a second radiation source is positioned juxtaposed said second sample vessel (24) for directing radiation through said second sample vessel onto a second detector (29) which measures and records any radiation passing through said second sample vessel, said evaluation region (3) includes a computer (32) which receives output signals from said density measuring instrument (20), said temperature sensor (21), and said first and second detectors (27 and 29), said computer evaluates the output signals and depending on the output signals directs signals to control said first and second pumps to reduce the flux mixture by adding thinner from said thinner supply container (12) to the recirculating container (11) and for pumping new flux from said supply container (13) to said flux recirculating container (11) and a valve (33) is provided in the fourth flux line (7) for removal of flux from the apparatus which contains a high water content.