The six-character Qianlong mark dates the bell to the tenth year of the reign of Qianlong, corresponding to 1746. And the three characters, bei yi ze, refer to a classical pitch.
This bell would have been one of sixteen bells, each with its own tone, which made up a bianzhong. These were suspended from a rack, and all were similar in size, shape and design. For an example see the bianzhong illustrated by Wan Yi, et al., Daily Life in the Forbidden City, Hong Kong, 1989, pl. 43, where it is noted that the timbre of the bells 'is melodious and mellow, with a mystical quality'. Another bell, also dated to the tenth year of the reign of Qianlong, was included in the exhibition, Oriental Works of Art, The Oriental Art Gallery, London, June 1993, no. 136.
A very similar bell inscribed with the characters Yizhe was sold in these rooms, 21-22 September 1995, lot 492.