Photoelectric Comparison Spectrophotometer.

A Method for Measuring Bacterial Pigments by the Use of the Spectrophotometer and the Photoelectric Colorimeter.

A photoelectric spectrophotometer suitable for the measurement of vitamin A by the antimony-trichloride reaction.

The measurement by visual methods of the fleeting blue colour of vitamin A in the antimony-trichloride reaction presents considerable difficulties which can be largely overcome by the use of photoelectric methods with corresponding increase in accuracy. The photoelectric spectrophotometer now described was constructed in I 941 when no comparable instrument of this type was commercially availabl...

Quality Control of Belsk’s Dobson Spectrophotometer: Comparison with the European Sub-Standard Dobson Spectrophotometer and Satellite (OMI) Overpasses

The total ozone measurements by Belsk’s Dobson spectrophotometer have been compared with the satellite total ozone taken during the OMI (on board of Aura spacecraft) overpasses for the period August 2004 – July 2006. The agreement between both data sets is much better if the results of the recent (June 2005) calibration campaign of Belsk’s Dobson at Hohenpeissenberg are incorporated to the stan...

Suction spectrophotometer cell.

A spectrophotometer cuvet is described which is emptied by suction without removal from the instrument. The use of this cuvet saves time and minimizes the chance of breakage. Data from C " measurements and absorbances of a dye solution show minimal retention error from successive specimens. expended in determining the absonbances of a large series of individual samples in a spectrophotometer ca...

Concerning Hertz’ photoelectric effect

Experimental evidence of the photoelectric effect goes back to H. Hertz. It occurred during the famous confirmation experiments of the Maxwellian theory. It is commonly held however that it cannot be explained in the framework of that theory. We are calling attention to some aspects linked with the interpretation of that effect on which, in our opinion, it is worth-