Check the listing for details. Pie Frequency Calibrator With Totalizer Model 541. Condition: Used. Listed at 899.00 USD. The Pie Frequency Calibrator with Totalizer Model 541 is a specialized tool used in the industrial and business sectors for accurate calibration of piezoelectric sensors and transducers. This calibrator allows for precise measurement and calibration of frequencies, making it ideal for ensuring the reliability and performance of various industrial equipment. With its totalizer feature, this calibrator provides a comprehensive solution for maintaining optimal frequency levels in a wide range of applications.