| 摘要 |
<p>1,218,119. Monitoring solution concentration. SIEMENS A.G. May 16, 1968 [May 26, 1967], No.23452/68. Heading G1A. [Also in Division G3] In a method and apparatus for monitoring the concentration of an aqueous potassium hydroxide solution by measuring the optical absorption of infrared radiation a wavelength in one of the following ranges is used: 0À95u to 0À98u, 0À99u to 1À05u, 1À07u to 1À14u, and 1À17u to 1À31u. The concentration is maintained within limits by a regulator 16 Fig. 2, responsive to the difference in the absorption of rays 9, 10 in test and standard cells 8, 7 the difference in intensity in the two beams, detected by photo-transducers 13, 14, controlling the regulator through a circuit 15.</p> |
