The new Model CTF Mini Tuning Fork Level Switch from the Proximity Division of Dwyer Instruments, Inc., is for level control of powders and liquids. The CTF incorporates a piezoelectric crystal that vibrates the fork at its natural frequency. When the fork comes in contact with a material, the vibration is dampened and the switch changes state. As the fork becomes free of material, the switch changes back to its normal state. The unit is not affected by vibration from conveying systems, motors, or the movement of material. Its compact size and DIN connection allow for application in places where a larger tuning fork level switch may not be suitable. No calibration is required and there are no mechanical moving parts, meaning no routine maintenance. The tuning fork level switch is not affected by the dielectric constant of the sensed material, making it superior to a comparable capacitance level switch for applications where the dielectric constant is low. The tuning fork level switch is also a good fit for applications when the bulk density is too low for a rotating paddle level switch, making it suited for low-density bulk solids and liquids.