Evaluation of tuning fork type force transducer for use as a transfer standard

Abstract Tuning fork type force transducers have potentially better long-term stability than conventional strain gauge types. This is because they directly convert applied force to resonant frequency, a conversion mechanism which is inherently insensitive to the inherent characteristics of elastic bodies utilized in force transducers. A new force transducer of 50 N rated capacity has been developed herein, and adopts a double-ended tuning fork (DETF) sensing unit. The performance of two such DETF force transducers was evaluated using the 500 N force standard machine at the National Metrology Institute of Japan (NMIJ). While realizing fine resolutions comparable to those of the conventional strain gauge type force transducers, the DETF force transducers were found to have low creep, low hysteresis, low temperature coefficient and superior long-term stability.