| OCR Text |
Show - 7 - rotation angle / 3o = - 9 encompasses a sufficiently wide range of angles. The constants given above are valid for sugar concentrations between 40$ and 60$. They can be altered at higher sugar concentrations, as one of us earlier was able to show. ( 5) 3. Choice of pH- value for the buffered sugar solution. Inversion rate of the buffered sugar solution is altered with the hydrogen ion concentration according to Equation 1: When eT- measurements "( in a given locality) are planned for short periods and low temperatures are expected, the inversion rate can be increased by raising the hydrogen ion concentration. When longer research periods are planned with expectation of higher temperatures, the inversion rate can be diminished by reduction of the ion concentration. In subalpine and alpine zones, pH- values between 2.5 and 3,0 are very satisfactory on the cooler north slopes as well as for measurements on south exposures; the research period can last from a few weeks to several months. It is essential that the hydrogen ion concentration of the buffered sugar solution be known exactly. It must be determined as accurately as possible prior to setting out the ampoules in the field, and entered in Equation 3 for calculation of the inversion constants. The hydrogen ion concentration does not change within the sterile ampoules Even after year- long research periods, no change in pH can be detected in ampoules left in the field. ( end of translated section) The authors go on to describe use of the sugar solution ampoules in the field and various factors affecting them. The significant points in this part |
