Application Information
A-2 100-214-239 Rev. A
NOTE
i All baths need a magnetic stirrer.
For smaller volumes with less than 30 seconds treatment time, an ice-water bath is sufficient.
For longer periods, especially when high power is required, a lower temperature bath is
required.
Vessel Capacity and Speed of Temperature Rise
The smaller the volume, the more difficult the cooling procedure becomes. For example, using
any given po wer input, to treat 5 ml for a long period would require a cooling bath of approx-
imately -35°C to maintain the sample at or below 5°C. In comparison, the processing of 200
ml would require a cooling bath of only 0°C to maintain the sample temperature.
Table 2 shows typical temperature rises f or sample sizes of 25 ml and 100 ml, using a 250 Dig-
ital Sonifier. A polyethylene container was used, with a 1/2 inch (12.7 mm) diameter probe with
a probe depth of 1/2 inch (12.7 mm) and a starting temperature of 25°C. "Average Difference"
was the average difference among duplicate runs.
Table 1: Temperature Rise Variations
Sample Size 25 ml 100 ml
Amplitude Setting
(%)
30 70 100 30 70 100
Seconds
30 30.0° 35.0° 42.0° 26.5° 27.5° 29.3°
60 34.0° 45.0° 55/6° 27.5° 30.3° 33.5°
120 42.0° 61.0° 78.0° 30.0° 35.0° 41.3°
180 48.5° 74.0° 90.0° 32.0° 39.3° 48.0°
240 54.5° 82.5° 95.0° 34.0° 44.0° 54.5°
300 60.0° 88.0° 95.0° 36.0° 48.0° 60.0°
Average Difference ±0.7° ±0.4° ±0.4° ±0° ±0.2° ±1.6°
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