Frequently Asked Questions About The Sonifier®
Standard Sonifier® products operate at a nominal frequency of 20 kHz or 20,000 cycles per second. The auto-tuning feature actually moves the frequency within a small range during operation to optimize performance.
Replaceable tips are generally used in high-energy applications where tip wear is expected. As energy is transmitted from the horn tip, traces of metal are eroded. Over time, this results in light pitting. Tips can be polished with crocus paper or emery cloth until they are out of dimensional tolerance. When this happens, the horn will be difficult to tune, may squeal, and eventually crack. As tips are relatively inexpensive, it is recommended that they be changed after the second polishing.
Microtips are designed to be used in small containers and are therefore quite thin. This smaller dimensional cross-section makes them more susceptible to stress cracking at higher amplitudes.
The two primary factors for effective processing of a given sample size are horn diameter and delivered power. The two must work together for optimal performance. Too little power and a large horn will stall. Too much power and horn damage may result. Branson offers a range of horns with each of their Sonifiers® that have been proven effective with that particular unit.
A "booster" is a device which is inserted between the converter and the horn. It mechanically increases the horn amplitude by some factor. They are typically used in difficult applications or flow-through applications where exposure time is very limited.
Hazardous materials may be safely processed with a sealed atmosphere horn. This device isolates the process sample in a sealed chamber during the entire cycle. It is available with external cooling and is also used in cases where there is need for metric evaluation of reaction components.
For processing larger volumes or a continuous flow of material, Branson offers flow-through processing cells. These specialized chambers permit the continuous flow of material through a high-density ultrasonic field. Volumes as high as 40 liters per hour can be reached with a single unit.
The greatest difficulty with processing small samples is providing good horn/sample contact. This can be improved by using a process container with a conical bottom. This increases liquid depth for easier horn tip immersion without increasing liquid volume. The bottom of an Eppendorf cell is often used for this purpose. A 3/32" or 1/8" microtip should be used and care should be exercised to not touch the side of the container with the horn.